I'm trying to fix my friend's computer - it's a HP Pavilion a620n with an Asus A7V8X-LA motherboard. The problem is that the computer doesn't want to post when turned on. No monitor activity, no beeps, just the fans turn on and the power and HD LEDs are lit. When the computer is powered, all of the keyboard lights flash quickly then turn off.
So far I've checked the PSU (a 250w HiPro) and there were no bad caps (all were Teapo). 5vsb is at 5.15v, so it should be good. All other rails are in spec, too. My friend said he also tried a different PSU and that didn't help.
I've also tried disconnecting everything and tested only the motherboard with the processor (an Athlon XP 3200+), both with and without RAM. Motherboard did not beep or give an error message when there was no RAM installed. Also tested with and without the AGP graphics card (motherboard has onboard video) - that didn't make a difference either.
Finally I tried resetting the CMOS via the motherboard jumpers as per the motherboard manual. With everything disconnected from the motherboard (except for the CPU, CPU fan, and SYS fan) and the CMOS reset, computer still wouldn't post or turn on the monitor.
Is it possible that the caps are bad, or is there something else wrong based on the above symptoms? I can power the computer on and off from the front switch just fine, which is telling me that the southbridge is working. So that leaves me with either a bad CPU (unlikely) or something else wrong with the motherboard.
As for the caps, none of them looked bulged. The motherboard has:
3x United Chemicon KZE 16v 1200uF 10mm dia. (VRM high)
8x Elite EB 6.3v 1500uF 8mm dia. (VRM low)
18x Ost RLS 6.3v 1000uF 8mm dia. (scattered throughout the board).
So, any ideas or thoughts?
Thanks.
So far I've checked the PSU (a 250w HiPro) and there were no bad caps (all were Teapo). 5vsb is at 5.15v, so it should be good. All other rails are in spec, too. My friend said he also tried a different PSU and that didn't help.
I've also tried disconnecting everything and tested only the motherboard with the processor (an Athlon XP 3200+), both with and without RAM. Motherboard did not beep or give an error message when there was no RAM installed. Also tested with and without the AGP graphics card (motherboard has onboard video) - that didn't make a difference either.
Finally I tried resetting the CMOS via the motherboard jumpers as per the motherboard manual. With everything disconnected from the motherboard (except for the CPU, CPU fan, and SYS fan) and the CMOS reset, computer still wouldn't post or turn on the monitor.
Is it possible that the caps are bad, or is there something else wrong based on the above symptoms? I can power the computer on and off from the front switch just fine, which is telling me that the southbridge is working. So that leaves me with either a bad CPU (unlikely) or something else wrong with the motherboard.
As for the caps, none of them looked bulged. The motherboard has:
3x United Chemicon KZE 16v 1200uF 10mm dia. (VRM high)
8x Elite EB 6.3v 1500uF 8mm dia. (VRM low)
18x Ost RLS 6.3v 1000uF 8mm dia. (scattered throughout the board).
So, any ideas or thoughts?
Thanks.
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