Hi, hope I've put enough specs in profile for you to help. I have a Compaq Presario 6735s I bought around 2008. CPU quite slow but graphics card not bad so made decision to upgrade. Looked up the laptop manual here to find compatible CPUs for motherboard, socket type etc. Went through 3 different (*****ic) buys before I found one that actually fitted. Now with everything reassembled, screen will flash up once upon powering on, then nothing. All usual lights come on, even my wireless connects, makes usual start up noises, fan, dvd drive etc .... Proceeded to take everything apart again, re-connected everything I tampered with. Even RAM, which I didn't have to remove before. Still same reaction starting up. Really frustrated with myself as thought this would be the right one. Could honestly cry, haha. I read the tutorial on here called 'No POST' to no avail either. I really hope it can come back from this. One last thing I can think of (before pulling new CPU out) is upgrading BIOS to support new CPU but with no screen I am stuck. Can someone please give me a little direction?