Garbled video on tc1100 (by 2 users)

Sorry for the long reply, but I hope this helps.

You will need to replace the system board and the keyboard receiving bracket inside the computer to fix this problem.

I work at an institution that uses these laptops and we've seen this repair a lot... and I personally have a tc1100 that has gone through 5 system boards. HP has a new (slightly redesigned?) keyboard receiving bracket that helps (but doesnt always) remedy this problem. HP themselves told us that we need to replace the systemboard, keyboard bracket and keyboard when we see this problem on one of our machines. We replace them all the time at our repair shop and it is the only thing that consistently works.

Note: The system board's connections near the graphics controller can be severed (its a multilayered board so you might not be able to see it if you looked) when the keyboard can move inside the keyboard bracket thus causing your garbled / checkerboard screen.

For this reason, you can sometimes temporarily get it to boot correctly by tilting the screen towards you all the way before turning it on. We've also seen some cases where disconnecting the keyboard and trying to boot will work. You can use those ideas only as temporary fixes though, and I'm sorry to say that this problem will get progressively worse until you repair it.