pc was on and running fine left it for about an hour came back to the pc in standby mode,then i click the mouse to turn it on but nothing happened,this has happened before so thought ok just reboot,so power off button for a couple of seconds then on again...powers up but nothing else so tried again looking for the flashing lights to tell me that its booting up..still nothing.on my mouse i have a light telling me it has power but it does not light up my dvd drive does not open (i know i can open it manualy tho)so started thinking psu had gone or partially anyway so i changed my 450watt psu for my old one 370watt psu (graphic card needs 400watt to run) too see if that would make a difference but to no avail still the same so swapped it back again
any help would be appreciated