Computer not booting but will restart

[adrenox]

hi im fairly new to this so please respond as thought I don't know anything about computers,

my computer wont boot after being turned off, it will spin the fans but then shut down... in order to turn it on I must basically get lucky and reach a screen where it gives the option to restart. when I restart it from that screen it works perfectly and will run all day, I can even restart it from here and it will turn straight back on but if I shut down it wont turn back on... I have no idea whats going on here, any ideas?

Not sure these are 100% accurate:
Graphics card: XFX Radeon HD 6870
CPU: Intel i5
RAM: 8gb Corsair Vengence (2x4gb)
Hard drive: 1tb Samsung
Power supply: 230v ATX

[Calum]

Welcome to the forums.

You can use a program called Speccy to get more detailed information about your system, which will help us to help you.
From what you've said, the problem sounds like what is known as a cold boot issue.  This kind of problem can be caused by several things, so once we know some more detailed information about your PC we can start narrowing it down.

[aQuilla]

hi im fairly new to this so please respond as thought I don't know anything about computers,

my computer wont boot after being turned off, it will spin the fans but then shut down... in order to turn it on I must basically get lucky and reach a screen where it gives the option to restart. when I restart it from that screen it works perfectly and will run all day, I can even restart it from here and it will turn straight back on but if I shut down it wont turn back on... I have no idea whats going on here, any ideas?

Not sure these are 100% accurate:
Graphics card: XFX Radeon HD 6870
CPU: Intel i5
RAM: 8gb Corsair Vengence (2x4gb)
Hard drive: 1tb Samsung
Power supply: 230v ATX

this could be a RAM, PSU or MoBo problem (in particular order). Have you heard some beeps while starting up computer? This could dead us to rule out memory stick problems. Have you tried testing your RAM? Like inserting 1 stick at a time? Also I am not familiar with the wattage of your PSU. It might be that it oculd nor give enough power to your system so you could go test it out too.

[patio]

I don't think a 230W PSU will power an i5 system...especially with an addon vid card...

[Calum]

It's not a 230W PSU - it's 230V.  The actual make, model and wattage of the PSU are unknown thus far.