I have been puzzling over my in-laws' computer for a couple of weeks. My father-in-law was simply looking at web pages when apparently the display froze with a diagonal line on view.
Ever since then, the computer has failed to start correctly.
The XP machine passes the POST successfully and then goes to the options screen for safe mode/safe mode with networking etc (of course, it didn't used to do this but since it initially froze in use it has).
If 'start XP normally' (or similar) is selected, the screen blanks and nothing else happens (hard drive activity stops).
If any other safe mode is selected, the list of drivers loading scrolls up the screen and then the screen appears to scramble into several sections and everything freezes there.
I've tried going into VGA mode (after pressing F8) but that results in the same as 'start XP normally'.
I've also tried booting from the WindowsXP CD. This works to a point, but after a while of loading drivers, the machine freezes again (sometimes with a random collection of "-------" on screen).
I've opened the machine up, checked the fans, tried each of the 2 sticks of RAM individually, looked in BIOS (no obvious errors and the HDD is detected) and checked all connections to no avail. The graphics are onboard (and I don't have a graphics card which fits).
Can anybody shed any light on what to try next? I just can't get it past the safe mode options menu successfully.
Both I (and my in-laws) would be very grateful if somebody has any thoughts on what to do next.
From your description, my guess would be the GPU. In safe mode, or within the WinXp installation, only a very basic driver is used, accessing the most basic parts of the GPU. That would explain why you get there further. Also the horizontal line indicates Issues with the GPU. Since it's Onboard, its also possible, that the whole Mainboard got damaged.
You may now try to borrow some GPU to test it with that (possibility to break it, if your Mainboard is damaged too)
Bring it to an expert so he has the liability and you a higher safety.
Have you opened up the case to determine if the heatsinks were free of dust? I ask because you're using integrated graphics and overheating of the IGP (integrated graphics processor) will cause those kinds of symptoms.
Is the system a consumer desktop PC like an Acer, Compaq, Dell, Gateway, HP, ..., etc.? If it is, please post its brand and model number.
Thanks for the help. Just to let you know that, after waiting to borrow an old graphics card from work (which never happened) my in-laws decided to send the PC to the local PC repairs shop. It seems that a graphics card wouldn't have fixed it and that there were deeper-seated motherboard issues (and something else which my father-in-law can't remember). All sorted now.