Ive borrowed my brothers PS3 while he is on holiday, but cant get any life out of it.

He has a HD tv so would have been running it through that, but I am running through the Red,White and yellow cables (component?) and am getting nothing on my screen. The green light on the PS3 is glowing but there isnt a signal coming through to the tv :(

Any ideas if there is a switch to turn HD off and non HD on or something?

Sorted,

Press and hold on button for a few seconds

It's how the PS3 sets itself up. It will configure to the 'priority' connection, so if you then change cables (e.g red/white and yellow to HDMI) it won't recognise the new set up. To completely fix a 're-boot/factory reset' does the trick.

..... Or whatever you did:D