MBP will only start in Safe/Single User

In the absence of any suggestions, I'm reposting more succinctly, and with a clearer subject line.

Trying to sort out my partner's MBP 2,2, late 2006 I believe.

Have made a Carbon Copy Clone to an external drive, replaced the internal one, and tried to CCC back to the new drive. Screen froze almost at the end of the copy, except for the cursor, which acquired some black lines next to it.

Now, whatever disk we try to start it from - internal, external, optical, we get: Grey apple with sundial
Blue screen briefly
then garbled frozen screen, with cursor visible but immobile. Sometimes the Users login rectangle is partly visible, with 'restart' and 'sleep'.

Computer will start in Safe Mode, but still has same black lines next to cursor. It will start in Single User mode.

Have started it in Target mode, and reinstalled OS10.6.2 from another (newer) MBP. After install, the newer MacBook started perfectly from the problem machine's targeted drive.

I have reset the NVRAM and the SMC, have even tried resetting the firmware by removing one RAM stick and resetting the PRAM 3 times as suggested elsewhere on this forum.

Any suggestions?

Have attached images of screen on its most recent start-up (it's not always the same) and the cursor with its lines.

 

Wow! 403 people have looked at this, and not one suggestion as to what could be the matter

 

Thanks for the suggestion.

It actually did start from original grey disk, which fortunately I still have.

However AHT, even in extended test mode, reports no faults.

It won't start from Techtool Pro 6 disk, through starting from its own HD in Safe mode I could install TT Pro, which also reports no faults.

Both of these attempted boots result in different garbled screens.

Can't install 10.4.8 from original grey disk, as 10.6.2 is already on HD.

I'm really at a loss here - the symptoms seem to be somewhere between hardware and software problems, and have no idea how to pin it down any further.

 

No fix :-(

So I guess I have to assume we have a unique fault that none of the wonderfully knowledgeable folks on here has encountered before.

Last try - any suggestions as to where else we might go for help?

Thanks