HP15C displays gibberish. Is it broken?

[Marcovecchio]

Well, I just made a test with an old 12c, and my theory seems to be incorrect.. Removing the clock does not create this LCD pattern, so it's not possible to pinpoint it's a clock problem.

I would buy this machine with no expectations, it may serve as a parts donor, or with some luck, it may be fixed, but I wouldn't bet money on that!

Eduardo