First post, by TbirdAthlon
Hello Everyone,
I have an old Asus A7V v1.02 board that I bought new back in the day that I'm trying to resurrect after at least a decade of not being used but it was a very reliable setup for years when was using it. The original working setup is/was an Athlon 1.1Ghz, two 256MB DIMMs, Nvidia GeForce2 GTS AGP video, Adaptec 29160 PCI SCSI controller, SB Live PCI sound card, and Intel 1xGE PCI NIC. If I remember when I last tried to use the machine (>10 years ago), I think it was becoming unreliable to turn on and/or sometimes it would just power off. The current behavior tested in a simplified configuration consisting of the motherboard, CPU, RAM, video card or no video card and PCI post card setup ONLY is that the machine will 99% power up via the soft-power switch, the PCI post card will show good power LEDs, the reset LED lights up and then goes off, sequence through a few different post codes (C0 -> C1 -> 48 --> C0 -> C1 ), stopping on displaying "C1", the PC speaker will give one long beep (not super long.. lets call it medium long) and then power off. I have tried the following but nothing helped to keep it powered up and get to a BIOS post:
- inspected the board for any obvious capacitor or other component issues (burns, cold solder joints, etc)
- brushed off the motherboard of any dust, etc
- removed, cleaned and re-applied new Arctic Silver thermal compound between the CPU and the quality CPU fan. I confirmed I didn't use too little / too much and everything i evenly spread
- tried across three different ATX power supplies
- tried a different CPU fan to see if it's a "too slow" RPM issue
- tried different RAM (one and two other sticks installed at the same time)
- Sprayed contact cleaner in the DIMM slots and inserted / ejected the DIMMs a few times
- tried disabling the "Jumper free BIOS mechanism and set the various DIP switches and jumpers for a 100Mhz buss * 11x multiplier for a 1100Mhz Athlon CPU. That did speed up the initial power to single-beep time but the motherboard still powers off within say 1.5 seconds.
It might be worth noting that if I remove ALL RAM and power up the system, it will go through almost all the same steps as above but the post card will stop on code "DE" and it will just keep giving that one single medium-long beep in an endless loop. That I totally expect but when any RAM is installed, the MB powers off.
I think part of the power-on issue I was experiencing a decade ago was a failing power switch as I recently confirmed with a multi-meter that it wouldn't give me any continuity at all. I just sprayed in some Deoxit and that seems to have fixed the switch but even with manually shorting the "power on/off" soft pins on the motherboard, the MB rarely occasionally won't do anything. Sometimes it instantly reacts like you would expect but other times it does nothing! Other times (rarely), the MB will power on, go through the above sequence but not power off yet never post. Maybe there could be some power on circuit issues here?
For completeness, the various capacitors on board are:
Main board
- size: very small caps : color: black : manufacturer: teapo : common value: 100uF 16v : other identifying codes: none
- size: small caps : color: black : manufacturer: rubycon : common value: 1000uF 6.3v : other identifying codes: YXG
- size: medium caps : color: black : manufacturer: JEC : common value: 470uF 16v : other identifying codes: none
- size: tall caps : color: black : manufacturer: rubycon : common value: 1500uF 16v : other identifying codes: ZL
- size: tall caps : color: purple : manufacturer: rubycon : common value: 1500uF 16v : other identifying codes: YXG
rear / VRM like vertical board
- size: medium caps : color: yellow : manufacturer: Fujitsu ? : common value: 680uF 6.3v : other identifying codes: none
- size: short/squat caps : color: lighter purple : manufacturer: oscon : common value: cannot rear : other identifying codes: SP
I don't know if it would be worth re-cap'ing this board but I can do it if there is high confidence that would solve this issue.
Other posts here on Vogons and other places say it might be a dead CPU or dead motherboard. I suppose either of those are possible and I don't have spare CPUs or MBs to do any A/B testing with. Can anyone recommend other things to try here? I'd love to resurrect this board if possible.
--David