Team-BHP - Weird computer bootup problem

Hello friends

Today evening after coming back from collage when I tried to start computer it refused completely. There was no response when I pressed power button on CPU. So called computer guy he thought since its with power SMPS must have gone bust. So he came replaced SMPS but still same thing.
Then next guess was CMOS battery. Tried replacing it but no luck.
This is where really interesting and weird part starts.
After removing power cord and removing battery, if I put battery into its place first and then attach power cord computer starts directly. And it works just fine. Only I have to adjust date and time and it works like there is nothing wrong.

The computer guy is gonna take CPU tomorrow to check motherboard. So I wanted to ask is there anything which I can do which will solve this problem?
Will I have to replace motherboard ?
Waiting for reply.

after it starts normally ..if u shoutdown and restarts wat happens ?
If it starts properply ....then how come MB is gone ? ..it could be bios settings ..cpu clock seetings might be problem ...if u have more than one memory cards (RAM) ...try starting with only one card and isolate the problem...aslo check the grounding ..if the case is giving u small shocks if u touch it..?

Hmmm very weird case. Doesnt look like anything's gonna be wrong wit ur motherboard or processor. Might be some problem with the power supplu ( the box with the cables n fan etc)... Give it for check up and see. How old is the comp???

Most likely it could be a problem with the BIOS on your motherboard.

Or, like it happened in case of my dad's comp, there was a certain capacitor on the motherboard which used to get overcharged at times, and used to shutdown the system abruptly, after which it would not come up. Removing all sources of power used to help get it out of deadlock.

If it is something like that, then a professional h/w engineer will be able to replace that faulty part for you at a low cost. Though make sure that your service guy is really trustworthy and doesnt fleece you with the wrong reasons.

Dude - post your config - it'll help us.

1. check the battery voltage with a multimeter - IIRC - it should be ~3v
2. swap out your sticks of ram - try running with only one stick which works for sure.
3. any error beeps on bootup ? - if you have the d-bracket with the LED's , whats the light config ?
4. remove the power switch connector from the mobo and try starting by shorting the terminals with a screwdriver - for all you know, it's just a loose connection in the power switch
5. are you overclocking anything - run the bios on fail safe defaults first

My money's on your mobo gone bad but you never know....

(I can feel your pain - ive been experiencing a run of problems over teh last one year - omne mobo dead (gigabyte km400vm rev 2.0) , 3 6800GT's PCI-E.....2 hdd's , and one mobo - MSI neo4 ultra showing the infamous battery drain problem now- I'm going to get the earthing done again and see if it helps - and put a big stabilizer on the mains)

Hello friends,
thank you for your quick response. I finally managed to trace problem.
No its not BIOS its not Mother Board its no RAM
its faulty power switch :eek: (literally the button which I push on CPU)

I remembered having feature in BIOS which starts the computer as soon as mains power supply is switched ON (in my case its UPS) so thought to give it a shot & walla it worked. I switched off computer again & it worked again. and it is still working.

It seems that once battery is removed for next reboot computer starts when mains is ON and then previous settings are restored.

Thank you for offering help everyone. Really appreciate it.