My Vaio all-in-one PC (VPCL11M1E) does not start after shut down or after entering hibernation/sleep mode. It takes 20 to 30 trials to get the PC back & running. The green & orange lamps do not turn on, and the ventilator does not start. It just won't turn on... then, suddenly after trying many many times, it works.

I re-formated the disk; I restored the machine to the default settings, but this doesn't change anything. All the Vaio updates are done, and also the Windows 7 updates.

Is this a hardware issue? a software issue? Rebooting works...

many thanks for your help!