PC does not start at all.

[patkim]

My PC does not start. Only the Power LED glows, CPU, PSU fan does not start.

However PSU fan starts if I remove the CPU Power supply (4 Pin connector) from mobo and hit Start button!
Any help troubleshooting this wud be gr8.
Thx

[delhiuser]

Not sure, but, may be SMPS problem.

[pimpom]

@OP: When asking for help with a hardware problem, it's always a good idea to post your configuration in detail. Otherwise, those who can help you have very little to go on with. They have to waste time asking you about your system and they may make the wrong assumptions. Many will simply ignore your post.

[saswat23]

^^Yup thats right.

[patkim]

It’s AMD Athlon 64 CPU, MSI Mobo, 512 MB DDR1 RAM based PC. It’s around 3 years old.
Have done some troubleshooting and this is what is happening.

When I Press the PowerOn button, the CPU Fan runs for approx 1 – 2 sec and then system shuts down immediately. So seems like it’s not even reaching BIOS.
I have checked PSU separately and ruled out any issues with it. Tried with another PSU and same result.

Tested the system separately outside the cabinet with only mobo, CPU with heatsink fan. Even RAM was removed. Still same behavior.
However if I unplug the CPU 12V supply and poweron, then PSU starts and is stable and so does the CPU fan runs. Since CPU power is off, no processing is happening though.

[topgear]

^^ check the cpu and mobo.

[nbaztec]

@OP 99% mobo is bad. No, scratch that, 100% mobo is bad. The fans will spin when you remove the 12V 4-pin connector, but the pc won't start & mobo wont POST. Try removing a RAM, if the mobo POSTs continuously, look for problem elsewhere. My guess is it will POST once (coz of RAM & then shutdown).

I speak this from experience, as with me everything that can go wrong with a mobo has. Especially the MSI ones. Especially the E series. Avoid them.