What are the symptoms of a failing PSU?

[Peroxyde]

Hi,

The computer exhibits this behavior on cold boot (computer was off for the night and is powered on): the boot failed, monitor is blank. Sometimes, there is a repetitive long beep. Sometimes, there is no sound, nothing on screen. Even though, hard drive and all fans run OK.

I just leave the power on, and push the reset button, and the computer can boot OK.

When the computer is running, a warm reboot has no problem.

Config: Antec True power 480, probably 4 or 5 years old. CPU is D830, 130 W. 1 hard drive, on board video (S3 Unichrome).

Thanks in advance for any advice.

 

[C1]

Beep codes vary with MB manufacturers (& are different for different BIOS types). The IBM Code - Continuous beep seems right now the closest match & has meaning:
"No Power, Loose Card, or Short".

http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=guide_beep_codes

Recommendation is to strip back the system to the minimum (eg,remove HDDs & disable in the BIOS), turn off in BIOS features such as USB, LAN, AUDIO, etc. & remove all PCI cards except video, etc. (Reseat the video card, memory & onboard connectors for good measure. Use DEOXIT before reconnecting.) Attempt to energize the system in only the most primitive state of functionality.

If there is no problem, then slowly add back components/functionality until the problem is experienced. The added component should be your problem source. (Note: If there is successful operation at the most primitive state, then for the next phase, I plug in a floppy or CDROM & try to boot to DOS & put some time on the system & continue to test & build from there.)

If there still is a problem, you might want to try to swap out the PSU, but I suspect that the amount of cost, effort & time now will begin to be competitive with just getting a new MB, CPU & Memory (as a packaged deal).

 

[Peroxyde]

I have already tried to use the mobo in minimum state, only 1 DVD drive plugged in. I tend to think it is a short.

If there still is a problem, you might want to try to swap out the PSU, but I suspect that the amount of cost, effort & time now will begin to be competitive with just getting a new MB, CPU & Memory (as a packaged deal).

You get it exactly right. I have had all kind of misery with this old computer and now I regret I took it. I think I am going to throw it away.

 

[BTRY B 529th FA BN]

Wait. You do turn off the computer through the OS right? NOT BY THE PSU switch in the back, right?

You may also want to run Memtest HCI, to check the RAM

You can also check the PSU by using a digital multi meter from your local hardware store or a major one like Home Depot or Lowes. I forget which color coded wires me what but most of your rails can be checked by the 4 pin molex plug, a SATA plug is needed to check one of the volts too; I think it's the orange wire and you stick the probe into the back part of the SATA plug because there is no hole like on the molex plug, to stick the probe in on the SATA plug.

 

[Peroxyde]

Hi,

I shutdown by OS when I can. Sometimes when OS is stuck I shutdown by holding the computer power switch down for 4 seconds. I have discovered since that the OS hanging was due to bad RAM timing and had fixed it accordingly. Now no more hanging.

I don't have multimeter. Can borrow one. I can search the net for wiring color. I may do this later if I still have some courage.

The remaining problem is the heat out of the PSU. I have followed C1's advice to unplug all the unnecessary devices. During my previous tests, I have unplugged all except for the DVD drive. Now I tried it for the sake of completeness and surprisingly the computer seems to be more stable.

I wonder what's wrong between the board and the DVD drive, may be the cable? In anyway, I will look at it later. But this could be a fluke. This computer has a paranormal component somewhere! each time I touch something there is a different behavior.

 

[BTRY B 529th FA BN]

Check your hdd with HD tune; look in the "health" section. If you have bad sectors developing, that could be causing a problem. And any type of DVD, CD, drive will cause complete computer freezing and its usually to the component going bad.

 

[Peroxyde]

Check your hdd with HD tune; look in the "health" section. If you have bad sectors developing, that could be causing a problem. And any type of DVD, CD, drive will cause complete computer freezing and its usually to the component going bad.

Thank you for introducing HD Tune. Ran it (HD tune 2.55 the personal free version) Health say all OK, Error Test found no error. Will try to look at that DVD drive next.

 

[C1]

A possibility is just to buy a replacement PSU from FRYs Electronics & if that doesnt fix the problem then Frys will refund your money. (A lot of people do this all the time.)

If you do this, then while there ask about their policy on trying out memory too.

And while you are there, pick up a can of DEOXIT & use it on all your connectors including memory & PCI cards.

Here are some links to diagrams that will help test the PSU.

How to Manually Turn On:
http://www.techpowerup.com/articles/other/22

Thread that contains the ATX connector layout diagrams (see Gillbot):
http://forums.anandtech.com/showthread.php?t=2056029&highlight=

PS: I sympathize with you on all of this as I just had a similar issue. After vacuuming out my PC, during its use I began getting a CPU fault notification. (Its my old 3.06Ghz which is my research machine & which I love). After a lot of blood, sweat & tears I finally resolved the problem by cleaning & DEXOITing all connectors. (I believe that somehow the main MB power connector wasnt making good contact on one of the pins, but I'll tell you that you could never have deteremined that just by looking/feeling.)