VOGONS

Asus P5A-B the bios gives a -12v error

Topic actions

First post, by egbertjan

Posted on 
User metadata
Rank Member
Rank
Member

I have an ASUS p5a-b rev 1.04 motherboard with an AMD k6 550MHZ processor and it gives a -12v error in the bios see the picture.

The attachment BIOS1.jpg is no longer available

is actually 0,0V

I tried 3 different power supplies, 1 ATX and 2 AT power supplies, they all gave the same error on the -12V. See the pictures below for the specifications of the power supplies

1 The enermax e201p-v at power supply 200 Watt

The attachment enermax.jpg is no longer available

2 The Seasonic SSG-150g at power suppluy 150watt

The attachment seasonic.jpg is no longer available

3 The Startech ATXPOWER300 ATX power suppluy 300watt. Is a new power supply not used before

The attachment startech.jpg is no longer available

Does that mean a problem with the PSU or with the motherboard and can this cause problems for the operation of the PC? I haven't encountered any strange problems with the PC so far.
Who can tell me what the problem is here

Reply 1 of 2, by rasz_pl

Posted on 
User metadata
Rank l33t
Rank
l33t

There has been a lot of Asus boards experiencing monitoring chip failures (bad voltage reading). You can always measure on the ISA slot (be VERY careful, one probe slip and you can fry chipset), not that you will need -12V anyway.

https://github.com/raszpl/sigrok-disk FM/MFM/RLL decoder
https://github.com/raszpl/FIC-486-GAC-2-Cache-Module (AT&T Globalyst)
https://github.com/raszpl/386RC-16 ram board
https://github.com/raszpl/440BX Reference Design adapted to Kicad

Reply 2 of 2, by Horun

Posted on 
User metadata
Rank l33t++
Rank
l33t++

Agree with rasz_pl ! If the -12v measures OK then change the "halt on" in bios Standard Cmos page to "none".
added: and write it down on one of them yellow stickies and keep in the case or mobo box/bag for future reference if battery dies. Have been saved many time by my own notes IF I made them 😀

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window