If it's an i815 your 866 should work. Have you tried:

- resetting cmos
- another stick of PC-133 SDRam
- with an AGP or PCI VGA
- check individual components on another M/B.

I am not sure the PSU is really the culprit here. Have you tried the PSU on another mainboard?

flupke11 wrote on 2020-03-03, 21:10:

If it's an i815 your 866 should work. Have you tried: […]
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If it's an i815 your 866 should work. Have you tried:

- resetting cmos
- another stick of PC-133 SDRam
- with an AGP or PCI VGA
- check individual components on another M/B.

I am not sure the PSU is really the culprit here. Have you tried the PSU on another mainboard?

- I did reset cmos
- yes, the PSU works...the CPU and RAM also work, I've tried them on another board

It's either the PSU or the board and I'm starting to think it's the board, although the seller claims it works only with old PSUs, how old I'm not sure.

The only PSU-related thing left (if your PSUs are known-good) is negative voltages. Do your PSUs supply -5V and -12V? If not that could conceivably be what the seller is referring to. Not at all sure that's the case. I have the uATX version of this board and has never refused any PSU I threw at it - although I do actually generally use ATX 1.x PSUs with those lines, so can't be sure.

dionb wrote on 2020-03-03, 22:10:

The only PSU-related thing left (if your PSUs are known-good) is negative voltages. Do your PSUs supply -5V and -12V? If not that could conceivably be what the seller is referring to. Not at all sure that's the case. I have the uATX version of this board and has never refused any PSU I threw at it - although I do actually generally use ATX 1.x PSUs with those lines, so can't be sure.

Hmm, I'm not seeing -5V anywhere written on the side of the PSU. Can you link an example of a PSU that supplies negative voltages? What kind of PSU are you using with your 370 board?

I have a few retail ATX PSU from the late 90's to early 2000's and all during that time had -5v and -12v. There are still some made like this one at Amazon:
https://www.amazon.com/Coolmax-I-500-500W-Pow … /dp/B0081H7EDK/
But many new ones do not have the -5v and or -12v
A picture of one of my older 20pin ATX PSU for testing motherboards

I can't help with your problem but in defense of the seller, who is not me, a year or so ago I sold an old Matsonic slot 1 board with a p2 400 and ram on ebay. I had used the board for a while and it worked perfectly. Had it playing games the night before I shipped it. But sure enough the buyer could not get it to boot at all. I tried to help, even sent him to this forum. Ended up refunding his money and let him keep it. So I can tell you this stuff does happen.