The reason I am asking about this is because I just noticed that the BIOS voltage info screen for my Biostar M6TBD displays a value for -5v but that ATX 2.3 PSU I am using (Thermaltake TR2 430W ) does not supply -5v . I have not actually measured it though .
Is this a bogus reading or could the board actually be generating -5v for the ISA bus ?
Doubtful. Biostar tended to be focused on no or low frills motherboards. If you publish some high res board shots, we can try to play "spot the VRM".
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Asus P5A, Gigabyte GA-5AX and FIC PA-2013 does not generate -5volt from -12volt supply.
I have tried them all with a non -5volt PSU and they all generate "error" on reading -5volt.
Some of the boards generate an error message on boot, and some does only report when inside the BIOS.
EDIT:
On second thought, they might all generate an error message on boot.
This is actually of no issue as such. As the -5volt reading can be set to "ignore" within the BIOS of those
3 boards. Missing -5volt is not a big deal, when the ISA cards used, do not require -5volt.
Don't eat stuff off a 15 year old never cleaned cpu cooler.
Those cakes make you sick....
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001100 010010 011110 100001 101101 110011
I had a look at my MSI 6147 (ATX, Slot 1, BX, 1 ISA), the -5V rail is wired directly from the ATX connector to the ISA slot. There is no reg in case of a missing -5V rail (that was out of the current ATX specs).
But I had a look at an older machine (Compaq Deskpro 386s), the proprietary PSU does not supply -5V, so they added a 7905 reg next to the ISA slots.
Doubtful. Biostar tended to be focused on no or low frills motherboards. If you publish some high res board shots, we can try to play "spot the VRM".
Definitely not the best lighting or lens for a close-up board shot, but it will have to do for now.
I do not see anything close to the ISA slots that could be a linear regulator .
The small chip with nearly unreadable markings close to the ISA slots is a TL 74F32D , so definitely not a regulator .
Nothing there except a couple VRMs for the CPU.
All hail the Great Capacitor Brand Finder
Well I tried another PSU. It is an Arctic Cooling Fusion 550RF (reviewed at http://www.hardwaresecrets.com/arctic-cooling … pply-review/10/) while the previous one was a Thermaltake TR2 430W variant . I can confirm visually that the -5V pin is physically absent from the ATX connector on both PSUs (normal for ATX 2.x units), but the BIOS voltage sensor info displays shows a value for -5V . This value is most likely bogus, but since I neither need -5V (only card that I have that might need it is a PAS16 variant I have somewhere) nor would I want to have the board alarm me as to its absence, I guess I should be happy.
