First post, by dionb
- Rank
- l33t++
I've always wanted a slot A system and recently jumped when I had the chance. Today it arrived, a beautiful MSI MS-6167 with Athlon 500. Cosmetically it's in perfect shape with no indication of damage in shipping. Only concern there is that it was just wrapped in copious bubble wrap with no antistatic precautions. Seller indicated that it worked fine and booted Win98 immediately before being packed for shipping. I have no reason to doubt that.
However it's not doing much booting now, and the behaviour is puzzling:
- there's no soft power on: as soon as I turn on the ATX PSU, the board starts it up.
- if the CPU isn't installed, it won't do anything else, but the power stays on
- if the CPU is installed, POST seems to start (I see C0 on my diag card), but within a second the PSU over-current protection cuts in and cuts off the power
I've tried with two PSUs, a period FSP 300W unit with beefy 30A rating on the +5V line and a new Coolermaster 650W rated for 20A on the +5V. Behaviour is identical (apart from the old FSP needing about a minute for the over-current protection to reset where the new Coolermaster is ready to go again almost immediately). With CPU absent, the voltages are all nominal (+3.3V: 3.33V, +5V 5.07V, +12V 11.79V); given how fast the PSUs cut out with CPU present I didn't manage to measure voltages there.
My first guess was that PWR_ON might be shorted to GND, but 'm measuring 10kOhm between those two. Similarly, +5V to GND is giving me 0.5kOhm with CPU in place (or 0.6kOhm with CPU removed) and 12V 7.8kOhm. 3.3V to GND is a slightly more worrying 75Ohm, but that's still not short.
I'm puzzled and pulling blanks here - the fact the PSU only gets shorted out with CPU present would indicate an issue with the CPU, but the way it immediately draws power even without PSU suggests a problem on the motherboard. I'm tempted to think there are two separate issues here. Which wouldn't be a surprise with a battered abused board, but doesn't match with a board in apparently undamaged condition that was happily booting a few weeks ago. Any suggestions as to what I'm missing here or what I should test next?
