• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

PSU Going South?

M

Monk0101

Weaksauce
Joined
Oct 1, 2005
Messages
93
Hi Guys, I need a little advice.

I have a PC Power & Cooling Silencer 750. It is about two or three years old.

In over 20 years I have never had a PSU go bad. I always outgrew them first :) But, I think I may have one going bad. Unfortunately, I don't have another to swap out and test. I just wanted to run this by you guys before I go order a new one.

About two weeks ago I started having boot issues when the machine has been shut off for a few hours or more. Actually, most of the time I never got as far as boot. I would turn on the APC 1500 Backup UPS and when it is set, I push the power button on the computer. Everything starts to power up. The Power light comes on. The fans start spinning. I can hear the drives start. The computer gives me the single beep as always. Then in a few seconds, before I even see the Gigabyte splash screen, everything shuts down. Then in a few seconds the computer tries to start again. Repeat as above, over and over and over. The furthest I let it go was about 10 of these cycles.

The only way I can get it to boot is pull the AC plug out of the PSU and wait a few seconds and reinsert. Then hit the power button and most of the time the machine boots as if nothing was wrong. After I get the machine running, there is no apparent problem. Bios,Everest and my DVM all say the voltages are right on the money. CPU Temps are all in the low 30's.

What I have tried already:
Plug the computer in to the 120v outlet versus the UPS. - no change
Memtest - no issues after a few passes
Reseated PSU cables and video card - no change
Unhooked all USB devices - no change

So, I am thinking PSU. Does that make sense to you guys or is there something I missed? I always thought a PSU was like a light bulb. It was either good or bad, not sometimes good and sometimes bad.

Thanks for any input!
 
Are you overclocking? If so, go back to default and see if the problem repeats. Also, unplug the HDs/optical drive and see if the problem still manifests itself.

Question - if you're computer is in an endless reset loop, how did you run memtest? I don't understand how you know if the memory is good or not if you can't get so far as to boot to CD. Bad memory might do this. Try the system with one stick of RAM.

Did you clear the CMOS? Corrupted CMOS memory could definitely do this.

Since it's PC Power & Cooling, I'm tempted to point the finger at something else, but if you had another PS at hand it would be worthwhile to plug it in and see if that solves it.
 
I dealt with this b.s. back when I had the Antec NeoHE's + DFI Ultra-D's. Similar symptoms that point to only one thing - PSU issues.
 
Thanks Sharpie, because the PSU is PCP&C is the reason I am looking for another possibility.

I can eventually (so far) get the machine to boot if I break the cycle and physically pull the AC plug from the PSU. Then when I reinsert the plug, I have been able to get the machine to boot normally. That's how I was able to run Memtest.

I'll try your suggestions and report back.

Thanks,
 
I think you're wasting your time dude.

About two weeks ago I started having boot issues when the machine has been shut off for a few hours or more.
Click to expand...

This is straight out of bad PSU playbook. What does cold or warm boot have to do with a corrupted CMOS? CMOS doesn't care if it's warm or cold, which should eliminate any possibility of this being an issue. Secondly, you haven't mention recently flashing your BIOS or even changing OC settings for that matter, so again, very doubtful that it's CMOS related.
 
Mav451 said:
I think you're wasting your time dude.

This is straight out of bad PSU playbook. What does cold or warm boot have to do with a corrupted CMOS? CMOS doesn't care if it's warm or cold, which should eliminate any possibility of this being an issue. Secondly, you haven't mention recently flashing your BIOS or even changing OC settings for that matter, so again, very doubtful that it's CMOS related.
Click to expand...

I think it's worthwhile to test everything, it doesn't take all that long. If the system doesn't behave then get a new PS. If you can take a PS out of another PC to test with then that's even better.
 
OK, I disconnected the optical drive. Of course the machine booted right up. The issue only seems to come up when it has been off for a few hours. So I'll check in the morning.

No OC. Everything is running absolutely stock. No Bios update for a few months.

I just updated my sig. I had updated it before but didn't notice the 10 line limit. So the update didn't take. Which brings me to another thought. As you can see I show 8 HD. Actually there are 4 others I didn't list for a total of 12 HD. I have run this setup with this MB and the previous one for a few months with no issues until the past couple of weeks. Is it possible that all the drives, MB, CPU, and video card all trying to start at the same time is just sucking too much current causing the MB to detect a low voltage and saying "no thank you" and shutting down and trying again?
 
Monk0101 said:
Is it possible that all the drives, MB, CPU, and video card all trying to start at the same time is just sucking too much current causing the MB to detect a low voltage and saying "no thank you" and shutting down and trying again?
Click to expand...

No. Even with all those drives, your PC is still well within the capabilities of a 750W PSU.
 
OK, I turned the machine on today after it had been off overnight. It booted right up. The only change was disconnecting the optical drive. Maybe coincidence. I'll leave it disconnected and see what happens for the next few days.

Sharpie, If the optical drive is indeed the problem, would you explain this one to me? The optical drive was working fine. Why would it possibly cause a reboot cycle? Since the reboot was coming before the Gigabyte spash screen, about the only things the system had a chance to do was to decide, "yup, I have voltages, a cpu, a video card, memory, and some drives connected (and I am not even sure it cares about drives at this point)". I wouldn't think that until later when windows tries to load would it even look to see if any of the drives, especially the optical, are in working order. As I said before, the optical appeared to be in working order. But, removing the power to it seems, at least for right now, to fix/hide the problem. Would you be so kind as to enlighten me on this one?

Thanks!
 
I spoke too soon. This morning before I went to work and tonight I am back to the same restart cycles (with the optical drive still disconnected). Tonight I was able to get a DVM on the 12v line when the system was trying to boot. The readings were in the 11-11.5 range. So, I am assuming that the issue is with the PSU not able to supply the needed startup current. I agree that a 750 watt PCP&C with a 60 amp12v rail should not have an issue. So, I guess it is time to order a new supply and see about PCP&C 5 year waranty (that way I'll have a spare). I just checked and the PSU was purchased in Jan of 2007.

Thanks for the help working thru this!
 
The 12V rail must be running at 11.4V or higher to be compliant with the ATX spec, so if you're seeing 11-11.5V then that definitely makes me think it's a defective unit.
 
I went back with the DVM and got a good connection to the 12v line. The reading was right on 12v. So, I started to look elsewhere. Turns out the issue was memory. If I removed one pair of the two pair of Corsair XMS CM2X1024-8500C5D memory, the machine boots properly. The wierd part is that when I run Memtest on each of the suspect sticks (after I eventually get it to boot) Memtest reports no errors. The "good" pair boot fine as a pair or individually and runs thru Memtest with no issues. Guess this falls under "whatever"!

As a side note, I went the RMA way with Corsair. Their best suggestion was to try downgrading the memory from DDR2-1066 (which it is rated at) and use it at DDR2-667. Let's see, take what in it's day was premium memory and cripple it by 1/3 and use it that way. Fortunately, Zipzoomfly has the same memory on sale for $19.95 after MIR. I just went ahead and ordered that to get me thru for a few weeks until I can built a new I7 rig. To me it is worth the $20 not to have to mess around with the RMA. Heck the UPS charge to send corsair the bad memory would be about half the price of new memory.

At any rate guys, thanks for the input sorting this all out.

Take Care!
 
You must log in or register to reply here.
Back
Top