PC wont start

[smithy4ever27]

I left my pc on while i went down stairs for a cup of tea, when i returned my pc was of, i turned it on but only a light flashed for a sec. so i opened the case and turned it on again same happend plus the fan went round for about 2 sec. and advice

thanks

[ski]

Check the MB for any bulging, leaking, or ruptured capacitors.
If there are any, then replace the MB.

If they look ok, then do a barebones config with just the power supply, MB, CPU, RAM, video card, monitor, and KB.
If that works, then reinstall/reconnect all other cards and all drives one at a time until the problem resurfaces.
The last component added is the cause.

If the barebones does not work, then swap out the PS, MB, CPU, RAM, and video card.