HEXiGON's thread reminded me, I have a similar issue on a 80GB PS3 (a CECHK) that someone gave me to look at. When powered on, it will play the start-up noise but it gives me a black screen - the XMB doesn't appear. Tried on both AV and HDMI cables. Display reset does nothing. It'll go to safe mode, and I can navigate it till the cows come home and have no problems. Tried every single option, I can go through the entire set-up process (setting time, date, network, etc.) but every time it hits the XMB, black screen. Sometimes it freezes up as it gets to the end of the start-up noise, sometimes I can navigate blind but can't get anywhere. Most of the time it plays the end of the noise, there is a click, the display resets and then nothing. Sometimes the power button double-beeps at me when I attempt to switch off, but most of the time it beeps and flashes continuously until double beeping and powering down (aka software crash). Doesn't matter how long the consoles been on, it will suffer the same variety of issues, but never a yellow light. The fan is never noisy either, although slightly louder than my older 40GB model. Some sites tell me it's a symptom of a faulty hard drive, but I did a disc check using some recommended tool (I forget the name) and it supposedly checked out fine. Removing the drive gives to the typical missing drive error at high resolution, so I'm uncertain that it's a GPU issue. Is it worth buying a replacement drive, or is it more likely to be something more serious?
Clarified that, thanks. Actually, the first thing I tried but unfortunately it wasn't that simple a fix. Shame, really - I assumed it'd be a quick job. Have actually had video displayed through it several times - the set-up process works lovely with no crashes no matter how long I let it sit powered on, but never got it to show the XMB. I think I've ruled out an overheating issue too, as no matter whether the system is hot or cold the same thing happens.
I'm assuming you mean the HDD contacts - will do. As I can get video in other modes and the HDMI equally does not work after video reset, it is unlikely to be an issue with the connection between console and TV (unless anyone knows of a situation where a dodgy AV connection can stop the XMB starting correctly). As for Safe Mode, I have been through all the options available (after cloning the hard drive using dd) and none seem to work. The ones that should do basic maintenance complete then black-screen when it reboots, the ones that reset the console take me through the 'first run' setup process, then when the XMB starts it freezes as per usual. It *might* be freezing up during the hard drive restore process, but it's difficult to tell. I think I will attempt to acquire a new hard drive for it, as it means I can rule that issue out and move on.
Sounds like the same problem I have, it's overheating the GPU. However I can sometimes start a game and play for 10 minutes, but I doubt it's a HDD issue. Secondly have you tried the Fan trick, that blows all the dust out?