Computer sometimes turns on

[ediz551]

i have a hp slimline s3115 and when i turn it on the hdd spins up and so does the dvd drive but nothing is coming up on the screen and the hdd light doesnt come on.
but there are a few time that the computer turns on like there is nothing wrong with it

 

[Gimp]

Check that all cables are connected securely inside chassis.

 

[ediz551]

checked the cable still no luck

 

[Gimp]

checked the cable still no luck

Check you graphics card is seated correctly.

Check ram is seated.

Check hsf on top of cpu is secure if you can get into bios check temps.

If no signal on monitor check monitor is ok on another pc.

 

[ediz551]

Check you graphics card is seated correctly.

Check ram is seated.

Check hsf on top of cpu is secure if you can get into bios check temps.

If no signal on monitor check monitor is ok on another pc.

checked the graphics card, ram also tried with one stick of ram, cant get to the bios and monitor working fine

 

[Gimp]

Check it with the other stick of ram with not getting into bios would suggest that ram may be the culprit.

Strip pc down to cpu, ram and graphics card only connected boot if no signal persists hard drive and other devices are exlcuded.

The devices that need to be swapped out if you have or can get hold of spares is ram easiest, then graphics card, psu. the motherboard and cpu unlikely to have spares but if mobo was totally caput then nothing would come on.
If cpu then fans would spin up a quick flash of hd light and then nothing from hd possibly.