Power Supply?

[joerg]

I just baught a new system well kind of i used recycled drives from a compaq. I got my mobo(shuttle ak11) put in my new box(generic with generic 300wps) and installed win me(i know it sucks) installed all drivers and defraged hdd then after a few hour of running it locked up turned it back on it locked up agian decided to check cpu(750duron) temps everything ok set defaults i bios went back to windows locked up checked all wires and booted agian it locked up. and finally after about 3 days of this it refused to boot no bios no nuthin so i sent the mobo back to mwave.com. What i am wondering is if it could have really been my cheap powersupply? Thanks in advance.

[G]

As you suspect, it sounds to me as if you have a power supply problem. Each power supply completes internal checks and tests before allowing the system to start. If the test is successful, the power supply unit (PSU) sends a special signal to the motherboard called Power_Good (Power_OK or POK). If this signal is not continuously present, the computer does not run. Therefore, when the AC voltage dips and the power supply becomes over-stressed or overheated, the Power_Good signal goes down and forces a system reset or complete shutdown. You may or may not have experienced this symptom. However, your system has been suffering from system locks (sometimes attributed to software bugs which can be the case but it can also be related to PSU problems). As you did not replace your PSU you have experience the following. On powering on your system, it may seem dead but the fan(s) and hard disk drive(s) (HDDs) are running or not if the PSU is completely gone now. This is an example of a Power_Good, or should I say Power_Not-So-Good signal. This can be confirmed by conducting the following test. If your computer fails to boot up properly the first time you turn it on via the power switch but it subsequently boots up if you use the rest button or Ctrl-Alt-Del warm boot command, then, in all probability, there is a problem with the Power_Good timing and hence PSU.

The PSU powers the computer so it can operate, obviously, but it also ensures that the system does not run unless the power supplied is sufficient to operate the system properly. In short, the PSU actually prevents the computer from starting up or operating until all the correct power levels are present. This PSU seems to have deteriorated to this point now. Initially, it may have been that your computer’s Power_Good signal was good but then the PSU started to struggle. How does this aforementioned set-up work? The Power_Good signal is a +5V signal (with variations from +3.0 through +6.0) generated in the power supply when it has passed its internal self-tests and the output has stabilised (between 0.1 to 0.5 seconds after the power to the computer is switched on) the PSU sends the signal to the motherboard, where it is received by the processor timer chip, which controls the reset line to the processor. In the absence of Power_Good, the timer chip continually resets the processor, which prevents the system from running under bad or unstable power conditions. When the timer chip receives the Power_Good signal, it stops resetting the processor, and the processor begins executing whatever code is at address FFFF:0000 (usually the ROM BIOS). If the PSU cannot maintain proper outputs (such as when burnout’s occur), the Power_Good signal is withdrawn, and the processor is automatically reset. When the power output returns to its proper levels, the PSU regenerates the Power_Good signal and the system again begins operating (as if it is had been powered on). A resetting computer indicates a Power_Good abortive action and leading one to suspect a PSU problem. By withdrawing the Power_Good signal, the system should never use an erratic energy supply because it is stopped quickly (reset) rather than being allowed to operate using unstable or improper power levels. These power states or conditions can cause memory parity error problems (sometimes misdiagnosed as a memory problem but in fact a PSU problem), CMOS memory corruption and so on. These problems can be hard to pinpoint and misdiagnosis is common.

If your computer was supplied with a cheap PSUs as stated by you, it may not have proper Power_Good circuitry. Some motherboards are more sensitive to an improperly designed or improperly functioning Power_Good signal than others. Intermittent start-up problems like the ones you are experiencing are often the result of improper Power_Good signal timing. If you have installed additional devices, or upgraded your motherboard (not the motherboard at fault but its sensitivity is more apparent to this over-stressed PSU stated) then PSU seems at fault in some way. As your PSU was already marginalised or poorly engineered then replacing it with a high-quality PSU instead can easily rectify a PSU problem. Have a look at PCPower & Cooling at www.pcpowerandcooling.com (http://www.pcpowerandcooling.com)

PSUs often do not fail completely all at once (your did not); they can fail in an intermittent manner or allow fluctuating power levels to reach the system, which results in unstable operation (ah!) and damaged components. Does this sound familiar? You may be experiencing the following without knowing its cause. If not, then you might experience the problems listed below unless you rectify the PSU right away.

Your computer system is powered by your PSU, do not jeopardise the integrity of your data and the remaining computer components on a marginalised or defective PSU. Act now, and everything should work out ok.

Symptoms you are, or may experience, pertaining to a PSU problem are as follows:

 Any power-on or system start-up failures or lockups.
 Spontaneous rebooting or intermittent lockups during normal operation.
 Intermittent parity check or other memory-type errors.
 HDD and fan simultaneously failing to spin (no + 12V) (is this your systems symptoms too)
 Overheating due to fan failure.
 Small brownouts cause the system to reset.
 Electric shock felt on the case or connector
 Slight static discharges disrupt system operation.
 Removing devices eliminates problem.

The power supply is one of the most important components in your PC. Do yourself a favour and buy a new high-quality replacement.

I hope this is of help to you. Let me know how you get on.

All the best,
G

[joerg]

Tahnks for the lengthy replie i am going to get a new psu and was now wander if sparkle is a good brand and what elses is good affordable brand i have a 300w enermax with an enermax case that i am saving for a athlon system.

[G]

That is ok. Well I am just about to get the PC Power & Cooling Turbo-Cool 450ATX/ATX12V model with some additions (Silencer maybe and 80mm fan that goes on the back of the case behind the PSU fan). I have read that PC Power & Cooling are supplied by Sparkle PSUs of some form or other but it may not be true. Enermax is a respected supplier of high-quality PSUs. Another is SevenTeam (?). Unless you are going to have multiple HDDs and other devices in a Raid and/or SCSI set-up then a PSU of true wattage output of about 350W should be ok for you. Probably, even less than this. However, you do not want to keep on incrementally upgrading the PSU. This strategy ends up being expensive. Therefore buy one that surpasses any of your needs today and invest for the future.

The PSU supplies the blood, so to speak, for your computer system so make sure it is clean, and stable. The PSU supplies energy for every component for your computer system so it is important to make the correct decision. All the above manufactures will have the necessary specification and more. Not much that differentiates them, except maybe the cost.

May be others can come in on this post and give you more guidance. Mostly, you need to read their specification information and go from there.

All the best,
G

[elroy]

You said that you assembled this sytem in a new generic case. If you try a new PS and the problem goes away I would return the PS from this case for a replacement. I'm running a Duron 800@980, 7200 rpm hard drive, CD-RW, case fan and cpu fan on a generic 250 watt PS. No problems in 6 months.