PC does not start

Clarifications

By that do you mean PSU?

If so, have you checked your power lead? A dead fuse is all it takes!

working and suitable power supply the obvious problem is either ther motherboard or the processor.

Most motherboards have an LED power indicator on them if this is not working then them problem would be the motherboard.

However if this is working then the processor is at fault, however, if it is working it still could mean that either/both the processor and motherboard are fautly as the voltage supplied to the LED is not voltage critical.

If you have a meter you can check the voltage on the power supply and make sure you are getting a good reading. If that works and you are getting a light on the motherboard try checking the cpu. Try holding the heatsink down onto the cpu and firing up the computer. Sometimes if there is not a good connection between the heatsink and the computer the processor will not work also if there is not a good connection you may want to apply some thermalpaste between them just incase.

Try another processor and memory. It could be either so try both.

Please post back if you have any more problems or questions.

See this excellent 25 Jan'06 TR post by Greg Shultz:

http://tinyurl.com/5tl82j

( hey guys, im having problem with my pc... it does not turn its power on... what shall i do??? is my mother board has a problem??? i tried many power supply in my pc cause i thought its problem is its power but it does not work still... what shall i do???)

Start simple, have you checked the plug socket? Have you tried to plug some other device in the same plug to see if it works?
Have you looked at the M/B to see if there are problems like expaned caps or burn marks? Does it smell burnt? Have you tried to use your hard drive in another computer to see if may have gone bad?
Using other P/S is good if they are the same type or better, but depending on your M/B and it's age you may need a P/S that has a PS4 connector or some other type. And you need a P/S that can support the hardware that you are using.

So if you had a 250wt P/S and it failed you need a larger P/S, like a 400wt or more.
In short let us know a little more about your system and happened before it had stopped working.