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matrix311
02-06-2006, 03:51 PM
Hey there guru's, so here is my problem if anyone can shed some light on this subject. One of my machines hardware doctor keeps going off and it's notifying me that my -5 voltage is out of range. I'll have to post up a screenshot later tonight when I get home, but from what I know this is the problem.

I have the Abit TH7-RAID mbd with a P4 1.9GHz cpu on there. 768MB rambus pc800 ram, 128mb Ti4400, sblive, 160gb hdd, 350 watt psu.

When I open the mbd's hardware doctor it alerts me that the -5v is at about 3.3-3.5v which is below the normal limit and it alarms nonstop. I dont know what the -5 voltage is or what device utilizes it. If anyone knows please let me know.

I thought the powersupply was defective and not pushing enough voltage out, so I purchased a new 350 watt psu and same issue. Next I thought the mbd was bad so I purchased another brand new mbd, same identical model TH7-RAID from Abit and same issue yet. I then stripped every pci slot free and unplugged all my external devices and unplugged all hard drives, case fans cdrom drives ect.. I unpluged all of those from both the psu and the mbd. All I had connected to my mbd was the PSU, CPU, Memory and Vid Card.. issue continues on.

Next I swapped video cards, same issue continues.
Next I swapped processors, I put another 1.9GHz cpu in there that I have and same issue continues
Next I swapped the memory that was in there with another set of memory from another working computer, same issue continues

At this point i'm stumped because I have swapped every single component on this computer and the problem will not go away. Last resort i thought the new power supply I bought could have been defective, so I returned that to get another one that was like for like and problem continues. I honestly dont know what the problem is or why the -5 voltage is way to low, if anyone knows please help. I dont want to damage any components for having low voltage so whatever help or troubleshooting steps is greatly appreciated!

I will paypal anyone who can solve my problem.
Regards
Eric
masher
02-06-2006, 03:57 PM
AFAIK, the -5v rail isn't even part of the ATX spec any more. So if your mobo definitely requires it, you may be out of luck. But I'd suspect that it doesn't, and you're simply seeing a spurious alarm...those software based voltage monitors are notoriously inaccurate. See if you can shut off the alarm for that particular rail.
matrix311
02-06-2006, 04:00 PM
AFAIK, the -5v rail isn't even part of the ATX spec any more. So if your mobo definitely requires it, you may be out of luck. But I'd suspect that it doesn't, and you're simply seeing a spurious alarm...those software based voltage monitors are notoriously inaccurate. See if you can shut off the alarm for that particular rail.

Not so much the software, but If I load into the bios and look at the pc/health status in there. It shows -5v 0.00 in there. Where the software based one in windows shows it about 3.2-3.5 or so.
masher
02-06-2006, 04:12 PM
The only thing I know offhand that used -5v was some old onboard sound chips, so I wouldn't worry overmuch about it. If you can disable the alarm in Windows, I'd go with that.
matrix311
02-06-2006, 04:15 PM
The only thing I know offhand that used -5v was some old onboard sound chips, so I wouldn't worry overmuch about it. If you can disable the alarm in Windows, I'd go with that.

My mbd doesn't have integrated audio or video. I've disabled as much as I can and still no luck. What else do you think uses -5v?
ryan_975
02-06-2006, 04:23 PM
Sounds to me that either your PSU isn't supplying -5v, or your motherboard has no connection to -5v. Seeing that BIOS is reporting 0v and Widnows is reporting an obviously erroneous value, i'd say that -5v missing is a safe bet. My windows software reprots my 12v rail as 0.2v, my 5v as 1.3, etc. So I wouldn't bear much weight on windows reporting sofrware.
masher
02-06-2006, 04:24 PM
My mbd doesn't have integrated audio or video. I've disabled as much as I can and still no luck. What else do you think uses -5v?
If you have something that requires it, then you're going to see problems regardless. But its my guess you don't, and the alarm is reporting an "error" condition that doesn't exist. Can you not disable the alarm in the hardware monitor, or set a wider alarm range?
Paul_Johnson
02-06-2006, 07:30 PM
My mbd doesn't have integrated audio or video. I've disabled as much as I can and still no luck. What else do you think uses -5v?

ISA bus powered items.

And like masher said...just ignore it.