Lenovo ideapad 500 power off after 3 sec

[meraklinetx]

I have lenovo ideapad500 with the mother board of la-c851p it was working ok but when i open it and clean fan and replace thermal compaund , the system is not working anymore, the problem is :

When i press power button, the system is turns on with no display and fan does not spin and after 3 sec it powers off itself, i remove all battery, reset bios , préss power button about 30 sec . But still same, what might be the problem ?? What you advise

[peste]

Re: Lenovo ideapad 500 power off after 3 sec

remove everything, and from the beginning, maybe you made a short one! remove (wifi, cd, battery, etc.) and turn on the board, see what happens.

[meraklinetx]

Re: Lenovo ideapad 500 power off after 3 sec

remove everything, and from the beginning, maybe you made a short one! remove (wifi, cd, battery, etc.) and turn on the board, see what happens.

Dear peste, thanks your quick answer, i did what you told, the laptop is fixed now, when i remove the heatsink the laptop worked ,i think the problem was heatsink were contacting with the capacitors over gpu chip, (but the interesting point was the heatsink were coated with black protector bands) so i apply extra band to over the capacitors on gpu , applied new thermal paste again and installed the heatsink back, now the laptop is working properly, thanks for your advice and help

[ravi_1617]

Re: Lenovo ideapad 500 power off after 3 sec

Hi .same board , Shutdown at Lenovo logo. Than if i press power button again don't start until disconnect adapter .without ram stays on .board has GPU too more thing observed CMOS battery is draining very fast.

[ktmmotocross]

Re: Lenovo ideapad 500 power off after 3 sec

Hi .same board , Shutdown at Lenovo logo. Than if i press power button again don't start until disconnect adapter .without ram stays on .board has GPU too more thing observed CMOS battery is draining very fast.

check voltage on power button and resistance and voltage on RTC battery

[ravi_1617]

Re: Lenovo ideapad 500 power off after 3 sec

Thanks for replying
Just checked.
3.275 volts before on
2.966 during on
3.216 after shut off

CMOS shows 60 ohms

[ravi_1617]

Re: Lenovo ideapad 500 power off after 3 sec

Where to start from . Thanks

[mcplslg123]

Re: Lenovo ideapad 500 power off after 3 sec

Since you are getting display everytime, i dont think its RTC issue. I'll bet for bad kbc and suggest to replace it.

[ravi_1617]

Re: Lenovo ideapad 500 power off after 3 sec

Hi .same board , Shutdown at Lenovo logo. Than if i press power button again don't start until disconnect adapter .without ram stays on .board has GPU too more thing observed CMOS battery is draining very fast.

Hi ,Problem was of adaptor, user was using 2.25 Amps.Has to be 3. Amps above.
Thanks