First post, by w1ll14m
Dear fellow board members,
I recently bought 2 LS-486e boards, one of them is a non functioning board (rev C2) and I would love to revive this board. I was hoping that it was an easy fix, it turned out to be a bit more complicated. Maybe someone can give me a few hints to look for?
After the PSU powers on nothing happens, no beeps.
CPU I'm using to test is a Intel 486SX 33MHz
contains eeprom 27c1024, dumped the contents, it looked OK. verified a few bytes (bootblock). I also tried swapping it for a 29ee010. I think they are pin compatible.
Things that I already tested (with motherboard stripped):
* jumpers, OK
* main power from PSU, OK (Power supply runs other boards just fine, harddisks are spinning)
* 12, -12, 5, -5 pins checked for shorts, NONE
* 5 volt between cpu vss/vcc pins, OK
* Checked most (visible) caps for shorts or low ohms, NONE
Post card ISA:
with cpu:
* 3v3 led blinks 2 times then stays off (very short, direct after power on)
* 5+ led on
* 12+ volt led on
* Digits are off
Without cpu:
* 3v3+ led on
* 5+ led on
* 12+ led off
* digits are on but -- or 00
Post card PCI:
With cpu:
* +5 led on
* +12 led on
* -12 led on
* IRDY on
* CLK on
* RESET on
* sometimes displays 00 or --
without cpu:
* +5 led on
* +12 led on
* -12 led on
* IRDY 1 second bright, then dim
* CLK 1 second bright, then very dim
* RESET 1 second bright, then dim
