Computer Blew UP!!!!

[imac9556]

Hi,
I just turned on my other computer, the monitor lit up green and showed post, and is showed post, then all of a sudden, there was a big BOOM!, and then the computer restarted automatically, and no POST. So I turned off the computer, and then tried to turn it back on, nothing. Just plainly dead, dead, dead. So I turned off the surge protector and then turned it back on, and pushed the power button, there was a loud boom but no power, no post. That scared the hell out of me. Whats wrong with my computer? Thanks all! :t :t :t

[gibsinep]

Well your power supply probably exploded. It is known to happen to poor quality PS that are under too much load. Lets just hope that the explosion didn't take anything else with it. It could have taken everything or just the PS. Most lickley just the powersupply. Then next most lickely is motherboard,ps, cpu, video card.

Open the case and look for burn marks on your hardware

[Jawa]

Any smoke or firework effects? :eek:

[Ammok]

Make sure it's unplugged from the mains before you open it up, or you might go boom too.......

[Ape0r]

Did you remember to plug in your CPU fan?

[Paco103]

If you're opening that PSU, unplugged is not good enough. They can still hold thousands of volts in the caps, and any one of them could be lethal (though usually just a VERY painful shock:P - speaking from experience!). I wouldn't say don't open it - I would - but if you don't feel comfortable with electricity, don't probe around too much!

[smily_03]

its possible that something is overloading the power strip causing it to trip?

also, is it more of a boom as in like an explosion, or a pop like in a firecracker, or a crack like power arcing?

[fluffycow]

one time mine made this horrid burning smell and wouldn't turn on anymore. Mobo vid card power supply, all fried. We think it was the power supply that ruined everything. If you ask me, the power supply is the best bet on yours too. Im wondering if I should start a pc horror stories thread....

[Optimus Prime]

YEH! do it man, i wanna look see at the evilness modern PC's cause :)

[Paco103]

Horror thread!!!!!!!!!
The CLOWNS did it! They destroyed my computer!!!
CLOWNS are EVIL!

he he - our TV studio at my old high school does a slide show during off-air times with the news and bullitens, and a couple of the guys that were doing it put in a subliminal flash screen, you couldn't even tell it was there unless you froze it on the computer....but was bright big letters

"Look out behind you. . . .
IT'S A CLOWN!!!!!"

Seriously though, I think that'd be a fun thread!

[fluffycow]

Already made it under the sysopt community section of the forums, under the name "pc horror stories!"

[imac9556]

The CPU fan was plugged in, i think i am going to scrap the whole system for parts and check them with a new power supply and then sell them:
Anyone looking for parts?

Chaintech CT7-ATA w/ all accessories and manuals and drivers
AMD Athlon Slot A 700Mhz
6GB HD
56k Modem PCI
10/100 Ethernet PCI
Memory
Floppy Drives
CD-Burner
56x CD-ROM
Case
and much more...

Thanks

[Paco103]

If the system blew up, what would we want with it?! Unless you're giving it away - I'll make something work out of it, or atleast use the shiney HDD platters and make a clock or something. Those things are SOOO SHINY!!!! and there are some VERY powerful magnets in there!!!!

[fluffycow]

oh yeah, a couple days back me and my friend took apart an old hard drive, shiniest mirrors ive ever seen, seriously. They were spotlessly clean too, the inside of a hard drive looks so cool. If I had a digital camera i would take a picture of the platters, but it would look like i somehow took a picture of the camera they're so shiny. I didn't see any magnets in there , but I did see the reader head.

[Paco103]

New Hard drives might be kind of different, I haven't gotten my hands on anything over 1 gig to rip apart, and they're using higher density which requires smaller magnetic charges. On all the old drives, there's a piece of metal that the back of the reader arm sweeps over. (The long skinny side goes over the platters, the back, just looks like a counterbalance, sweeps over a chunk of metal.) It just LOOKS like regular metal, not like a magnet at all, but if you take them out, there's 2 in all the old drives I've done, and if you get a finger stuck between there, it can really hurt. I've actually seen someone get a small pinch of skin ripped off by them, just smashing together on a fingertip so fast. It's fun to hand them to someone and watch them get them apart! It's hard!

[Tremo]

No Paco, there isn't "thousands of volts" in the caps of a computer's power supply. You have a valid point, but the voltages in a computer are low. 3 volts, 5 volts, 12 volts, none are lethal.

Do unplug though.

[Ammok]

Tremo

Thats supply power as distributed to the board. There are not only thousands of volts in the psu caps, far more worringly there are at least thirteen amps. The voltage will whack you the amps will kill.:(

[mcool61]

Your ok most of the time as long as u stay out of the power supply. The hot stuff where the ac power comes in can kill. Its the amps that kill. Tesla used to hold bulbs of rarified gas in his hand & pass 10,000volts thru the air & himself to lite the bulbs. Turn of the century flourescent lighting.

[Bone Collector]

Just don't open your monitor because there is realy high voltage

:t :t

[kvk007]

that sucks! hope your cpu didn't die.

[Tremo]

Whoever thinks there are literally "thousands" of volts in the caps of a desktop PC power supply is smoking dope. No way, no how. Jeez.... I also see you don't know how ohm's law works.

[Mutant_Donkey]

i agree with him. uits not 1000. read the capacitors mounted on the PCB. ive read the larger ones, and they say 220v, 16v, 190v, etc. but nothing is near or exceeding the thousands. plus if you unplug the computer and press the power switch you should drain all current unless the PSU fuse is broken. if that is the case, lave the PSU sitting around for 24 hours, the electrons stored in the capacitors will eventually degrade to a weaker current as they are being stored, and the current remaining after 24 hours wont hurt you. some of you should open up your PSU and check if you doubt me. i had to change many fans in PSU's at my work, The Computer Den, and i've never got shocked, plus ive always made notes of the capacitors ratings.


in regards to your question, imac, it is most likely that a capacitor blew up in the PSU, which is a very common problem. I suggest reading the PSU by the pound article on tomshardware.com, and learn why manufacturers are sacrificing quality for price. I also recoomend you buy an Enermax or another good branded power supply in your next purchase. rember - its not wattage that counts, its the maximum amount of amperage the PSU can deliver. you can find out the amps by looking at the labeling sticker on the front of the PSU.

good luck.

[$1500-P4 gamer]

Originally posted by Ammok
Tremo

Thats supply power as distributed to the board. There are not only thousands of volts in the psu caps, far more worringly there are at least thirteen amps. The voltage will whack you the amps will kill.:(

right. Voltage is the presure atwhich the electrons are pushed. This is the part that burns your skin-ehhhhh!:(

Amps-i.e. current is the rate atwhich electrons flow from one given point to another (how packed together they are). that is the part that will kill you.

In all honesty our electronics teacher at school{who by the way was a profesor and wrote prog.s for the gov. for some time till his nerves got shot!} told me that you can be killded by like one milliamp at 1/2volt! Its enuff to set your heart beat out of wak is what happens. Miss a beat and your off your feet!:rolleyes: But then I have a heart murmer so I wonder how it would effect me? Anyhow your body is totally run off electricity so the dangers of messing with it are high. Also we are 98% water and it has salt to it aswell which makes for a real good conductor. Even the foods you eat can increase your ability to conduct electricity. To much info. I know-I'm rambling! Peace.;) :t

[$1500-P4 gamer]

Originally posted by Tremo
Whoever thinks there are literally "thousands" of volts in the caps of a desktop PC power supply is smoking dope. No way, no how. Jeez.... I also see you don't know how ohm's law works.

Ohms law is for beginers! LOL! Man you dont even know what you are talking about! Look here. 12volts at 1/4 farrad and 1 amp(many smaller caps hooked together) and what do you get-a sh*t load of volts. This is then converted to a lesser volts-which oh my yes increases the current supply (i.e. amps). My shop project 1st year was on caps. I made a 1 farrad cap out of smaller ones much like a psu has. Linked together with two bars as to connect them in parallel hooked'em up to a lantern battery for awhile and then after unhooking bat. struck a insulated handled screw driver over them. The flash was so bright I saw spots the rest of the day. Alot like welders flash which I also have had. The cap bar was welded to the screw driver PERMINATLY! The teacher then explained to the rest of the class my point. Dont mess with even smaller caps as they can be hooked up with others in the circuit resulting in ONE LARGE CAP. Mess with a tv and you will find out. That was year 3! By the way I got a A= on that project and NEVER got less than a A in electronics which I'm very proud of. You dont know electronics aswell as you think it shows in your post. So dont call anyone here stupid. Go ahead ask me-think you can stump me on basic electronics-go ahead I dare you. Just Jokeing LOL! AHha now I'm the one laughing. :p :t

P.S. I'm just bustin your chops-so dont get upset but next time look before you leap.;) :t

[$1500-P4 gamer]

" agree with him. uits not 1000. read the capacitors mounted on the PCB. ive read the larger ones, and they say 220v, 16v, 190v, etc. but nothing is near or exceeding the thousands."

I see your confusion but alas your wrong. See in electronics components are added together as to reach a higher power. Why? Well first off dif. circuit types these are complex meaining they are series and parallel and series to parallel and parallel with two series branches on and on and on. So I will just touch the basics here. By adding them together across certain paths you may touch it will = thousands of volts. A very large cap is very expensive. Smaller caps are cheap easy to find and easy to replace. They make less heat and waist less power aswell. Not to mention that you need several outputs as you mentioned. This is why they dont just use on biggen at what ever point. So no there is no thousand volt output-BUT if you touch the wrong part completeing a circuit that is complex of two units it will combine them resulting in a VERY high voltage=ouch or death. Its complicated and I understand the confusion but trust me its there. If you still dont understand I will make a longer post breaking it down better but I'm lazzy.;) :t

[$1500-P4 gamer]

Better yet wheres Bovon? Let him explain it for ya. Hehe!:t

[Mutant_Donkey]

i understand. but whats the probability of all the capacitors storing a very high electrical charge at once?

[Ammok]

Whats the chance of them all failing at once and blowing a computer to bits?:D LOL.:D Cheers P4, nice explanation.:t

[mcool61]

I bet some of u are too dense to conduct anyway so thread is redundant. sort of like me wearing a hardhat.:x

[$1500-P4 gamer]

Originally posted by mcool61
I bet some of u are too dense to conduct anyway so thread is redundant. sort of like me wearing a hardhat.:x

Hehe, LOL ;) :p :t

[$1500-P4 gamer]

Originally posted by Mutant_Donkey
i understand. but whats the probability of all the capacitors storing a very high electrical charge at once?

Caps are like batterys which are basically storage cells. Caps can hold a charge for a extreemly long time upwards of 100 years. But the way they work is they are charged up which takes very little time. The smaller the cap the quicker its charge. Then after this energy is stored it is discharged this all happens over and over very rapidly. Builing up and colapsing (discharging). The chances that they all are charged when turned off is extreemly high because of this. I have yet to find a large cap that wasnt charged (unless it was bad!) and then its usually blown apart like a resistor. I know this cause I discharge it before working on the unit. Get a good flash of electricity and it was charged. Give you a idea of how larger caps work some in the older tv's would take a day or two to discharge! Thats somthing else too-some discharge rapidly and some are deseigned specifically to discharge slowly. Ones in PSU's are rapid discharge. There are alot of dif types of caps and materials that they use. Generally higher end PSU's have better caps that will last longer.

When I used to make my own guitar effects from a schematic book I had in 1st year electronics-I was 16 then (noise gates/flangers/distortion/reverb/mixing panel-alot of em) I would experiment with replacing highend stuff with lower to se the effect. The book gave me a hint. Military grade IC's/caps/ and etc. have a better tolerance rating than off the shelf radio-shack. Like a resistor with a 10% tolerance would be like 5% or even really expensive 2.5%! By yanking the cheaper IC's and lower tolerance rated resistors and useing higher end caps-my effects I built sounded top notch. You would hear hums and noises with the cheaper stuuf. They were also more feedback prone. The highend components yielded a top quality sound. Music or in this case really sound can show how cheapr components can change the ratings of a circuit due to large tolerance rates. This realates directly to cheap PSU's that are explosion prone(not saying good ones cant!)-sorry I went overboard. Peace.:) :t

[Admiral Paddon]

Hey, what kind of HD is it? Internal, Ext. SCSI, IDE? Also, what kind of memory you got (Tech., size, etc.)?

How much for them?

[Tremo]

Yo P4, you're in over your head here, it's YOU who don't know what you're talking about. I'm a degreed electrical engineer with over 25 years industry experience, plus I taught a freshman lab during my senior year in college. I was working on this stuff while you were still loading your diapers. I've worked on and designed switching power supplies, I know how they work. I'm also very familiar with capacitors, how they work, how they're made, and the effects of hooking them in series and parallel.

Hooking a bunch of caps in parallel to get huge energy storage and then welding a screwdriver proves nothing, it only ruins the screwdriver. If they were charged with a lantern battery of 6 volts, you could have put your fingers across the terminals and felt nothing because your skin resistance is too high for there to be sufficient current flow. Get a clue on how this stuff really works before you embarrass yourself further.

There is not "thousands" of volts in a PC's power supply, no way, no how. If the supply topology directly switches off the AC line, then at most you'd have a couple hundred volts stored in the circuit before the switching section. Most of the energy storage is in the output filter section of the thing, where the operating voltages are 3, 5 and 12 volts, which won't hurt you.

Jeez..kids...

[Ammok]

Tremo

Transformers, ....robots in disguise......

now using your logic it says its safe to stick your hand in the back of a telly, after all only 240 volts is going in.... the plain fact of the matter is that the psu blew up and no engineer is going to say anything is "safe" with open and obvisiously closed mains voltage circuits live and kicking.

As for the 12volt line, he dosent have one at the moment, it blew up remember? Your advice is not safe, any peice of electrical equipment that has failed in such spectacular fashion should be, carefully, disconnect from the mains source and treated as lethal.

There are kids on this forum who will take your comments as being gospel and go screwing around in the pc thinking they are safe, the psu is in the pc, you really trying to tell me that they won't open that up as well? Geesh, only problem is that they won't be able to post back and tell us what happened.

Lets widen the discusion, whats the difference between an electric shock and electrocution?

[Tremo]

It goes without saying that before you open the thing up, it should be unplugged from the mains, particularly after a catastrophic failure. I thought everyone could figure that out, it should be obvious.

As a hobby, I repair vintage guitar amplifiers. Old ones using vacuum tubes (valves to you Brits). They routinely run the tubes at over 400 volts, and when working on them, sometimes you have to run them with all their guts exposed. Touch the wrong thing and you're on your ****.

I know what I'm doing, when it comes to high voltages, guys.

[Aarmenaa]

I'm no expert, but I'm betting they don't put all those little warning stickers on the side of a PSU for nothing. I've poked around in a couple of PSUs before, and I would bet that they're dangerous, even in good working order. Of course, as logical as that sounds, I don't have any proof, because I haven't even had a simple eletronics couse. Maybe I shoud look into one-before I really hurt myself-:r

-Aarmenaa

[Ammok]

I agree with you, you know what your doing. And I dare say most of us in our more mature years who have had several belts from the most unexpected sources of electricty will probably take a good deal of care when it comes to dodgy electrical devices. But not all here are experienced either electrically or electronically and it's always easy to pick up the wrong end of the stick.

I worked in an electronics firm where the sport was to pass power supplies from the bench test over to "engineers" to assemble the device., the sport being the number of the times the capacitors gave em a good belt. Just enough to numb your wrist mind and if it you weren't careful you got it yourself. Funny thing electricity, especially mains ac.

[$1500-P4 gamer]

For such a expert can you do simple math? Mutant_Donkey saw 220v, 16v, 190v and that not all of them and your already up to 470v and that only three caps-DUH! Next thing you gonna try and tell me is that caps dont hold a charge!

"Hooking a bunch of caps in parallel to get huge energy storage and then welding a screwdriver proves nothing, it only ruins the screwdriver. If they were charged with a lantern battery of 6 volts, you could have put your fingers across the terminals and felt nothing because your skin resistance is too high for there to be sufficient current flow. Get a clue on how this stuff really works before you embarrass yourself further."

First of all it keeps taking those 6volt untill it builds up to the capacity of the cap. First year electronics there! You should know that I guess but you didnt!

Alright now you really proved it! You have no idea do you! If you saw that flash-I think you would see it dif. Your telling me that a arc of juice that nearly blinds you isnt enuff to shock you! HUH????? Especially when my High tech lab teacher even said it only takes one milliamp at 1/2volt to kill you! Seeing how he did this and prog. for the gov. and hes a profesor I tend to believe him over you sorry! I have study electronics for a long time thats why I'm totally disregarding what you even said as it makes no sense what so ever. A flash of electricty bright enuff to blind you cant shock you? I still cant believe you even said that and calimed to be a expert in the same post-GOD! I'm not gonna waiste my time trying to make you understand-just go about playing with caps that are charged and wait for one to stop your heart! I know better and I was taught by a REAL expert who is way more experienced in this tuff than you-
:p :rolleyes: :t

[fluffycow]

p4 gamer, how do you make a multivibrator? whats a transistor? what are the two main types? what are the differences between the two? how do you make a transformer? what is electrolysis? Why are ni-cads used in remote control cars beside the fact that they are rechargeable? Why is grass green? Im 14 :), some people are scared of my electronics knowledge.

Its so weird, the more posts I see you make the more like me you seem.....scary.

[$1500-P4 gamer]

"Its so weird, the more posts I see you make the more like me you seem.....scary."

Why thank you. Coming from a inteligent young man like yourself thats quite a compliment.;) :)


Why are ni-cads used in remote control cars beside the fact that they are rechargeable?

Well because the have a lower memory of the discharge/charge there for hold a fuller charge over and over again. This is why you cycle them to keep them strong! By the way there are better batts. but they caost too much. Like the ones used in cams are far better but far more expensive-lithium. I know me batts. too.

As for grass. Its green cause of clorophil(SP?)
;)

Why its always greener on the other side I still have yet to figue out.-HeHe!

whats a transistor

A component that takes a lower volt input (trigger) to switch a higher volt through other two leads.

As for the rest I'm assuming you were trying to make a point. If you really want me to answer all that I will. But I'm too lazy as it seems you already know!

Been a rc hobbiest for along time now. Have a Traxxis stampede stadium truck (electric nicad) I use 1500mha because they give more power but for a shorter time run. Also have a Nitro-Duratrax Maximum Mt Monster truck 1/10scale oversized with a 1hp .16 tourqe motor. Soon to be a .21 the largest you can run on it. It has a billet aluminum flywheel and balancer a 4 shoe centrifical clutch and real universal joint driveshafts as well as 8 real ball bearing wheel bearing instead of bushing plus a exhaust header and pipe to replace hte factory exhaust. She's all hopped up beyond factory stuff and does 60+mph now! Going for 70mph:cool:.

Looking forward to future discusions with ya. Remeber to keep up with the electronics and always question everything, just cause somone tells you this is how it works dont forget to ask why!;) :t

[$1500-P4 gamer]

Got one for you. Whats a IC and when was it invented. Also what components did it replace?;) :t

[Paco103]

IC invented in the 70's I believe?! Integrated circuit, it is a tiny chip of silicon or other semi-conductor that is etched with 10's to thousands of resistors, transistors, diodes, and gates. It replaces - basically, resistors, transistors, diodes, and gates. A single chip can replace rooms full of components on a quarter sized chip. The transistor replaced the tube - which is probably more what most people are thinking! What's next on the trivia P4?

[fluffycow]

shoot, I just lost my whole post I was gonna do when I got disconnected, so im gonna make this one short. Sorry bout last post, I wasn't too nice :( . Your right about all the questions, and another reason they use nicads is they can put out more amps at a time becuase they have very little internal resistance. You seem pretty smart too, I was offensive earlier becuase I was thinking about this kid at school that always outdoes me :( . You've got a nice rc truck, ive got a trainer rc plane. Im thinking about an rc truck, but I really need all the funds I have right now for a computer. One thing is that at 60 mph one meduim sized rock would throw that thing to kingdom come :). Check out the rc airplane crash photo sites before you go for that 70 mph, becuase the crater would proly look about the same :). One other thing about transistors is that you can melt em if you apply a 6 volt battery backwards, they smell horrid though. Its also odd that some people really know so little about electronics that they are freaked out when I make things like lights that turn on when you touch two leads.

[fluffycow]

thanks a lot paco :( . I think it was 1979 when it was invented? It replaced the tube, as paco said. It is made by taking this base material, then adding another protection layer. The area where the little "wires" are going to go through have a laser or something shine on them and it hardens the second layer. The hardened parts resist the chemical bath that the die is put in, forming pathways. I think they make resistors using impurities? and they make transistors by having n and p semiconductive layers. I think they just make more layer by repeating or something. This is probably badly innacurate information becuase its off the top of my head, and it was at least a year ago when I looked up how they wrre made. The semiconductor layers are etched through silicon, which is basically purified melted sand. Nowadays whole oscillators, and things like op-amps and gates are all made of chips. Don't forget the most complex chiip of them all, the computer processor

[$1500-P4 gamer]

Actually the reason I brought up IC's is because you mentioned transistors which was the begining of it all. Pc's were what drove both to come into existance. Tubes were hot burned out quiet often and were totally unreliable. So Bell Laboratories invented the transistor in 1947, And as I said they are basically electronic switches-1 in feed wire trips the ciruit to connect the other two leads which usually is a higher volts or amps. This replaced the TUBE all together. Then in 1959 the IC was invented once again due to pc's. This eliminated the lenghty cicuits and transistors and other components etc. off the board and into one chip-the IC.

Your both right about what it is and how its made and what it replaced but your dates were a little off. Scary to think how long ago it all came about. PC's have driven electronics into a new era!

"One thing is that at 60 mph one meduim sized rock would throw that thing to kingdom come . Check out the rc airplane crash photo sites before you go for that 70 mph, becuase the crater would proly look about the same . "

Actually no. Its real stable. The chasis is solid aluminum and the plastic A frames are made of stress tech. There pat. method. They show a guy twisting them with a pair of pliars to prove it wont break and he lets go-it goes back to shape. Pretty awsome stuff-gone are the days of fragile plastic like my older rc's. Oh and they even have a life time warrenty on the stress tech parts. I had her full wound out one day and lost it around a corner, theres this stone curb made of mountain rock by my drive. Skidded right head on into it. The front wheel was dangling (must have flipped 10 times in the air) but the part flexed and just poped the a-frame pin out. Philips head screw driver and two secs. later I was in buisness. That really impressed me. That was stock speed before I hpoed it up but I'm sure it'll take a hard carah at 60mph. I have my own race track with HUGE jumps and figure eight off-road coarse. Also a oval track around the parimeter. Rented a back hoe/dozer for two days and made me a nice track. The one jump I have I clear the truck over my head every time. The one time I dont I'll prob. be knocked out as it weighs like 10lbs.:( My girlfreind is gonna stand under it and film me with her Sony Handycam (which was $900-last year) doing some crazy jumps for this rc car website I go to. I'll send you a pick of a mid air jump. I set music to it and make small mpeg1 videos out of it. Pretty neat. One guy lit gas and jumped his truck over it-but it caught on fire. Looked awsome but I'm sure he wasnt happy. He sent it in anway, the damage was done.;)


My truck (my baby) http://www.duratrax.com/cars/dtxd91x01.html

[$1500-P4 gamer]

"they are freaked out when I make things like lights that turn on when you touch two leads."

Yeah I know what you mean. I used to take digital clocks apart for the led display. Then make up a switch so I could change what the #'s were. That used to freak people out too, cause it would mess with their head one time it was 9-now it says 1999 what the----Hehe!;) You remind me of me alot when I was younger. Thats really cool.;) :t

[Tabraea]

WOW..!! You ain't kiddin' are ya?!?!? What was it?? Have to been in the case to investigate?

I've just been reading exerps from the thread.. I think if this happened to me, I'd have heart failure.!!

[fluffycow]

Thats cool, I thought that new stuff was just marketing. Like the geforce 4mx series... Even though I want an rc truck even more now doesn't change the fact that I can't afford it :(. I still say that hitting something sorta resembling a wall at 70 mph would turn that car into a crater, but its nice to know that it can take a minor (or medium) crash without any downtime. With I could say the same for my model plane. I have the feeling im gonna turn it into a heap of scrap one of these days. Atleast if I do I could use some of the parts to build my own rc car(rebuilding the plane would cost too much)

Ive never fudged around with my clocks before, but it sounds like a good idea for halloween. I set op an occilator(i know i spelled it wrong) to switch the words on the clock dont-smash-our-pumpkins :).
Or, I could do something really mean, buy a tilt sensor, hook it up to about 4 of those one time use cameras, and stick them all inside a pumpkin. When they pick it up to smash it it'l light up the entire front yard :x .

Wow, these threads seem to get off topic real quickly.... ;)

By the way, were you also tormented by classmates in school? It seems to go hand in hand with liking things like this...

But I don't care, nerds have all the fun

[knydegger]

I did the same thing with my computer. I thought it was a gun shot , it was so loud. So I turned it off , then on and nothing. I bought a new Power supply at Frys and put it in. All worked fine except mouse, so I bought a USB mouse, All was fine , then the keyboard didnt work, so I bought a usb keyboard. Then about 2 days later, the harddrive was acting weird, so I reformatted that.
It has been about a month now, and with every day use, it works perfect. Like a brand new computer!!!

[jkozura]

P4,
Since your professor that has so enraptured you has professed that .5V at 1 mA will kill you, did he go into other specifics? Like where the current had to be applied? What if I got a .5V, 1mA shock in my pinkie toe? Do you think I would die? what about on the end of my nose? Do you have to be submerged in a tub of water with ground leads out of your rear to die from that kind of shock? I think that you should take what amounts to "urban legends" like that with a grain of salt!
As for rhetorical questions, why does an electric fence not kill you when it shocks you with so many volts? Obviously there is a lot of current there if it will shock across 100 miles of wire, and through wet weeds!

http://www.electric-fence.net/cgi-bin/SoftCart.exe/Optional-110v-electric-fence-chargers.html?L+scstore+ctwg0757+1026967628

Of course there are conditions that can cause death or injury in almost all electronics, but that does not mean that you should act superstitiously about it.
Personally I think that both you and Tremo know quite a bit about electronics and electricity, but you are making the whole issue into a contest. Most of us really do not care who can pee farther! (glib reference to pissing contest)
The simple facts are that statistically speaking, imac's power supply blew a cap, and that it very well may be that with a suitable replacement soldered in there, the whole system may come back to life, working normally. You can't say that is as improbable as dying from .5V 1mA.
I am admittedly not the world expert on electronics, but I have a lot of experience where the rubber meets the road, not just tinkering.
In case you are wondering, I was trained in electronics by the US Air Force at Keesler AFB, MS, where I was an Honor Graduate with a 97.8 average.

http://www.keesler.af.mil/332.html

I think that you would love the place. Ever thought of enlisting?
After that, I was the Lead Technician in the computer repair dept. of ICBS.

http://www.icbsrepair.com

Talk to you later, and remember, although you may not like what I have said, I am not attacking you. I just think you could spend a little more time on topic, and remember that more than two people (you and your prof) can know a lot about something.
Thanks,
John Kozura IV MCP
IS Manager, AICPA/PDI
SSgt, USAF, honorably discharged

[jkozura]

By the way, I don't advocate that imac repair his power supply himself, either, unless he has electronics and soldering experience.
Imac, unless you have some training or experience, I think you should go get another power supply. A P/S is an easily replaceable unit, not very expensive, and will probably solve your problem.
Thanks,
John Kozura IV MCP

[dosmastr]

Originally posted by Paco103
If you're opening that PSU, unplugged is not good enough. They can still hold thousands of volts in the caps, and any one of them could be lethal (though usually just a VERY painful shock:P - speaking from experience!). I wouldn't say don't open it - I would - but if you don't feel comfortable with electricity, don't probe around too much!

ACTUALLY that doesn't seem incredibly correct!! (just like my spelling) if you were talking about moniters i'd say yes with the line added below but think about it, a psu has to take 110V or maybe 220V and output 5V and 12V why would any electrician in thier right mind punch the voltage up to "thousands of volts" if they were only going to use another rectifier to step down the voltage to the 12V and 5V rails of the unit. current and voltage are not the same thing.
caps can hold a significant amount of current... however even large caps will only hold a charge for minutes, at most a couple hours ************* anyone who tells you otherwise is not a very well informed electrician.

i've opened up power supplys and touched all kinds of stuff in there, haven't gotten shocked except when the thing was on (i didn't know the heatsinks were electrified during operation too)

but to be safe just wait a couple hours, maybe even leave the 3rd pin on the power cord (the ground) plugged in. before playing with the thing.

[Ammok]

Grief, current degrades over distance, thats why you have massive great transformers to boost the voltage to an ultra high level and transmit it to the next transformer that then switches it back to low volt high current. Volts equals current times resistance and if you can hold resistance relatively stable then increase one parameter, will decrease the other.

You need a very small amount of current to transmit high voltage over a long distance. I could go into skin transmission, reactance and eddy currents, not to mention three phase and vectored inductance and capacitance, but why bother. Electricity Kills the unwary and a good few of the wary. Don't mess with it.

[johncampanale]

[QUOTE]Originally posted by $1500-P4 gamer
[B]For such a expert can you do simple math? Mutant_Donkey saw 220v, 16v, 190v and that not all of them and your already up to 470v and that only three caps-DUH! Next thing you gonna try and tell me is that caps dont hold a charge!

Please get your facts stright before you post your messages.
The voltages that you and Mutant_Donkey listed are "Max. Working Voltage" for the cap. It is the max voltage that the cap be used at. That is approx 20% higher than you would normally use, ie reserve. Again it is the max working voltage of the cap. I can take a 10,000 volt cap and put 6volts into it and it has a "charge" of 6volts.

"Hooking a bunch of caps in parallel to get huge energy storage and then welding a screwdriver proves nothing, it only ruins the screwdriver. If they were charged with a lantern battery of 6 volts, you could have put your fingers across the terminals and felt nothing because your skin resistance is too high for there to be sufficient current flow. Get a clue on how this stuff really works before you embarrass yourself further."


First of all it keeps taking those 6volt untill it builds up to the capacity of the cap. First year electronics there! You should know that I guess but you didnt!


Alright now you really proved it! You have no idea do you! If you saw that flash-I think you would see it dif. Your telling me that a arc of juice that nearly blinds you isnt enuff to shock you! HUH?????

You should think again before you made that statement as well. Lick both of your fingers real good, go into the engine compartment of a car and touch the battery leads, one finger on each lead. Did you feel anything, I don't think so, but take that screwdriver and short it across those battery leads and see how big that flash is right before that battery gets REAL hot and spits acid all over you and everything else when it explodes.

6 volts is 6 volts. amps are amps. Please think before you post, don't trust that just because someone said something, it's the truth.

John Campanale
ps. the 2nd anode on the crt of a modern monitor is approx 27-35K(that's thousand) volts but at very small amps, like 20mA, it will shock and sting you but unless when you are backing away from or recoiling from the shock or maybe have a heart problem it will NOT kill you. I know, i've been hit by it many times.

John

[johncampanale]

Originally posted by $1500-P4 gamer [/i]
Actually the reason I brought up IC's is because you mentioned transistors which was the begining of it all. Pc's were what drove both to come into existance. Tubes were hot burned out quiet often and were totally unreliable. So Bell Laboratories invented the transistor in 1947, And as I said they are basically electronic switches-1 in feed wire trips the ciruit to connect the other two leads which usually is a higher volts or amps. This replaced the TUBE all together.

Actually, it took a long time to replace a tube, as a tube has no distortion, ie no switching required, it's on or off, whereas a transistor has a switching voltage where distortion occurs. AND it was the hi-fi market that drove transistor design not pc's, and it took awhile to build a transistor amp that would proform as well as a tube amp.

John Campanale

[fluffycow]

Actually, johns kinda right about transistors, nowadays very very few applications actually still use tubes. Ive noticed the distortions, and also the small voltage leakage, becuase a transistor is never totally off. If you build an extremely sensitive amplifier, you will notice that sometimes its constantly on. Unless you use really good transistors....

Quote: "caps can hold a significant amount of current... however even large caps will only hold a charge for minutes, at most a couple hours ************* anyone who tells you otherwise is not a very well informed electrician. "

Caps can hold a voltage for a long time, I was searching through my electronics parts box and using a led to discharge caps I hadn't used in years. Its true that most don't stay charged long WHEN THEY ARE BEING DISCHARGED! Whenever you use a voltage meter to test the power in a cap, it slowly discharges it. So it appears that the cap is discharging itself.

I wouldn't touch a car battery after you have licked your fingers.... I presume you havent tryed it? IM GUESSING IT HAS THE SAME EFFECT AS TOUCHING A 9 VOLT TO YOUR TOUNGE. ONLY WITH 480 AMPS. Your skin has decent resistance when its dry, but don't forget that your body is filled with water. The charge that car batteries hold is massive, don't mess around with one.

The charge in caps has to do with farads, a farad is a measurement of the amount of electron charge is something like 1000000000 electrons, but I don't feel like looking it up.
uf is one 100000'th of a farad is i remember right.

I have a bunch of 2000 uf caps, and one 10000 uf cap. I usually charge them with 3-6 volts. They are pretty harmless, but only at the voltage I charged them. Charge them with their max of 30 volts, and you could get some big sparks. Im pretty sure the amount of amps you charge a cap with only changes the charge rate. Charging one with a 9 volt takes longer than with 9 volts worth of c batteries.

[$1500-P4 gamer]

No hard feelings. We can have two dif. opinions. You seem to know alot about electronics too.:t

[$1500-P4 gamer]

As far as I got shocked by this or that and it didnt kill me so its safe. Thats not the right way to look at it at all. I mean I got zapped by a electric water heater-220v and it was heating the water so full current draw. Arched between the two probes as I was going to check for continuity at the thermistat. ( I was told it was turned off!!!) the probes melted into my finger tips! The meter exploded and it was a $100 digital model! I couldnt let go and my hair was on end for a while do to the static discharge. It didnt kill-but yet It certainly could have very easily. I've also got zapped by electronic ignitions on cars and there thousands of volt at a good amperage. You can feel it numb your whole arm and then kick you back. Did it kill me-no. But again it could have and it could have also hurt me by my reaction to it -=i.e. bump head etc. It takes just the right moment in time-and it can set your heart off beat. Thats what my teacher was explaining-and he didnt make it up, it was a article he brought into calass. Its based on how much it takes to cause your heart to stop for a moment. Now its true that that little will prob. never hurt you. I've been shocked more times than I can remember-err thats prob. why I cant remember-hehe. BUT it scientifically can and has! This article was really good- wish it wasnt so long ago I would remember what mag. it was in. Point was he had proof. Its true and I do thouroughly believe him. He was just trying to make a point of how sensitive are bodys are to electricity seeing how it runs our entire bodys. Food is basically converted into power down the road in our bodys. Our body run off this power. Hence the muscle spasm you get when shocked. It messes up your motor skills-since shocks sent from your brain are what causes your muscles to move.

Now the point of this wasnt to make everyone paranoid just to make you think before getting into any electronic device that says HIGH VOLTAGE or whatnot. I mean not all of us here that read this stuff know electronics and I'd hate to hear that someone tried to fix a PSU from advice here-and they got shocked/burned hurt-etc. Especially when they are soooo cheap-why even chance it? Of course all of us that responded to this thread know this but its the ones who are reading and dont know that I want to be cautious-as we already know to be. Peace!

[Mordegan]

Next time you build a pc, make sure you spend a bit more on a better case and power supply. IT's really worth it !!!!!! AMD systems prefer good psu's.:D

[fluffycow]

Anyone who does something dangerous becuase of what we said on the forums is a fool :)


Quote: "You should think again before you made that statement as well. Lick both of your fingers real good, go into the engine compartment of a car and touch the battery leads, one finger on each lead. Did you feel anything, I don't think so,"
(one example of a reason why you shouldn't listen to us)


another: "Ive never fudged around with my clocks before, but it sounds like a good idea for halloween. I set op an occilator(i know i spelled it wrong) to switch the words on the clock dont-smash-our-pumpkins .
Or, I could do something really mean, buy a tilt sensor, hook it up to about 4 of those one time use cameras, and stick them all inside a pumpkin. When they pick it up to smash it it'l light up the entire front yard."
(an example of how legimate posts can degrade into random babble)


P4 gamer sounds like someone who would like fidling with boxes of electric motors, breadboards and transistors, my room would be bliss :)