no display - can't get to CMOS - can't boot
trying to help a friend who was given old PM8400B mobo with pentium mmx P55c cpu 166 MHz/award pnp bios, smm/smi power management with apm.
- no display
- monitor light flashes green
- power light is on
- fans are on
- keyboard flashes (num lock, cap lock, scroll lock) then stops responding
- monitor is working (tested on my system)
- mouse is working (tested on my system)
- keyboard is working (tested on my system)
not sure what to try next?
how do i wake monitor?
if i clear CMOS (jumper on mobo) will that clear the monitor sleep mode?
thank you in advance for your assistance.
Last edited by dallover; 02-17-2002 at 08:28 AM.
Welcome to SysOpt we are happy to have you here.
The one thing I can think of right now is do you hear any (POST)beeps. If you don't hear any beeps it could be mobo or CPU that is defective. You can check the Award BIOS beep codes here.
howdy much! thank you for the welcome! glad to be here!
i should have listed the beeps (or lack thereof) above! no POST beeps! i read the following with respect to no beeps:
If the LED on the front of the monitor is
tried this, with no results.
yellow or flashing green, the monitor is in power-saving mode. Move the mouse or press Alt+Tab on the keyboard and wait up to one minute to wake up the system if the system is turned on.
i know there are myriad irq conflicts from the brief glimpse i got of the device manager (sound card - no drivers installed; apm with exclamation point, etc.) this all started when the serial mouse wasn't recognized by system and asked for ps/2 mouse (no ps/2 port had been installed).
thanks for the suggestions much! i'll keep trying! i keep hoping to find my way into the CMOS or into DOS to check out the configuration . . . .
If the machine has an AGP video card, take it out, rub the contacts with a pencil eraser...clean the eraser residue good with a lint free cloth, replace the card. Be sure the card is seated well. If an AGP card has risen up at the rear any at all, it will fail. It must be seated front to rear completely.
Try a different video card, even a PCI card if the inservice is AGP.
Try resetting the bios to its defaults. Many boards have a jumper for this. If you do not have the manual, or do not know where this jumper is, remove the bios battery overnight to reset the bios.
hey bovon! thank you for the suggestions! i have cousins in murrell's inlet! love it back there!
this is an PM8400B (still looking for manuals) mobo (according to documentation sent), via VX pro chipset pcb2c437 ultra dma 33, pentium p54c/p55c processor, award bios pci/pnp 586, 4 pci & 4 isa bus slots and a 12 pin power adapter. she was given the computer as a gift but no software, manuals, or peripherals. win98 is installed. however, there were myriad conflicts from beginning (opti vga display adapter 82c931 - no drivers, apm has conflict, serial mouse is not recognized and he didn't install the ps/2 inboard mouse port, no fans, etc.) i'm trying to help out with the limited knowledge in have as she doesn't know anything about computers.
i believe he's overclocked the board and this may be playing a part - hard to tell without manual, etc. if i could get to the bios it might become more apparent!
i have an old s3 adapter i could try. should i reset the cmos using the onboard jumper first?
thank you bovon! have a great day!
Well, sence you do not have a manual, it will be diffucult to locate the onboard bios-clear jumper, if there is one. Most all new motherboards will have it, but not too many of the old ones. If the jumper is there, it should be a 3 pin jumper block and the jumper will probably be on pins 1 and 2. The way to clear the bios is to put the jumper on pins 2 and 3 for perhaps an hour. The jumper block should be near the bios chip or the battery. Removing the battery overnight does the same thing. The battery holds the bios active while the computer is turned off. There are some capacitors there that charge up, acting like a battery. These hold the charge voltage to the bios while a battery is being replaced. Some will dischage pretty quick...a couple of hours maybe, others will hold a charge for much longer. If the battery is one of the round...oversized watch type batteries in a holder, you can try this. Unplug the computer from the AC wall socket to get all power off of it. Take the battery out of its holder, and get a small screwdriver or something simular and place a short between the metal contacts that work the battery when its in the socket. Hold this short several minutes and reconnect everything. If that dosn't work, remove the battery over night to be sure. (get a wad of aluminum foil balled up and stick that in the battery socket with the battery out for an hour, jusy be sure it is making contact with both of the battery connectors.)
A manual would certainly be nice, and that PM8400B sounds like it may be an Intel pentium board. Tomorrow I will do some looking around for a web site that may have a manual.
Do try another video card if possible.
Is this the critter? http://www.amptron.com/html/pm8400b.html
Manual included. Hope this helps ya...
thanks bovon and rocket!
i found the amptron site earlier and printed out the manual (what there is of it). it, of course does not match the board in this computer! it's close.
i'm going to reset cmos using jumper and, when that succeeds, i'll use a bios utility to find out the processor for certain.
hopefully, this will work as it is really not worth the time and effort to make this one work (can get a pentium 200 complete with monitor for $120 from the State of California Surplus Equipment Warehouse down the street!!!)
thank you both for your assistance!
wish me luck!!!!!
I took a look at the board from the link above. You say its close?..how close. I have seen the same model board that was the same as another, except for minor changes. If this board is close enough, the jumpers should do the same, even if they are not in the same exact place on the board you are looking at.
One thing does bother me tho, you said in your first post that it is a P55C 166 mhz cpu. From what I am reading here for that board, it does not support 166 mhz. Looks like 75 mhz max.
Look at JP 3, the CPU speed settings and tell me what pins the jumper is on, A..B..C 1-2, or 2-3 ect.
You may want to pull the cpu out of the socket and read on the chip what it is if you suspect it has been overclocked ect.
There is a possibility that the case speaker is dead, and the POST beeps that should have been heard are not being heard.
RAM could be a problem as well, especially if POST beeps are there, but not being heard.
From what you said earlier about mouse problems ect, it looks to me like it did boot into Windows at some point?..if so, the machine is not dead, but I don't quite understand now what has happened sence...like maybe it did boot at one time...even with problems, now it just appears that the monitor will not wake up?.
Last edited by Bovon; 02-18-2002 at 02:42 PM.
Look at the manuals.The model is there.
thanks rex! i've been there, however, there is some question as to the "true identity" of the chipset and mobo. i believed that P55C 166 MHz was correct as the 2 pages that peggy received from her benefactor showed PM8400B from amptron.
however, the board is slightly different. there is a JP3d jumper; the version # on mobo reads 5.2A; the pci and usb chipsets reference PM8400C amd vx pro +.
bovon, my mistake about the 166 -- it states on the printout that he is going for a 233 .JP3a = 2-3; JP3b = 1-2; JP3c = 2-3; JP3d = 2-3there is a special note regarding the CPU clock speed jumpers. it states:
i replaced the speaker already without any sound resulting. next on the agenda: clear the CMOS????
to get a 3.5x multiplier for the intel & amd 233 MHz processors you will need to set th ejamper settings to 1.5x; the system board will automatically set the clock multiplier for 3.5x for those pcoessors when sert to 1.5x.
thank you both for all your help!!
Last edited by dallover; 02-19-2002 at 05:06 AM.
UNDERclock it !
set the fsb mb speed to 66 or less and set the cpu multiple to 3.5 or LESS -- 3 , 2.5 , 2
i know it sounds crazy but i had an 350/100 with 100 mhz ram that went bad - so i had to use 66 ram and boy you can grab a calculator a figure the fooling around i did
i think i picked 4.5 x 75 = 337.5
i also used to enjoy "simulating" slower comps 166 , 200 , 233 etc
Hey Dave, you don't live too far away from me.
howdy dave! i'm sure that the "lesser" ones appreciated your kindness!
if i underclock, will it boot past post? i'm beginning to feeling it would be less time-consuming to just buy her a slightly more current mobo without any legacy/other problems?
thank you for the help! i'll have to brush up on my underclocking!!!
if you overclock past the cpu's tolerance it's guaranteed to lock it up The AMD K6's are notorious for it -- and 12.5 % and that's it
i think i ran it as low as 2 * 60 mhz = 120 on a 350
and i'm not sure if everybody else would agree but it can't hurt to reset the cmos - bios - mb with the jumper or just pulling the battery
make sure the board is set up correctly otherwise and lowering the cpu multiple is the best - it only affects the processor