F1 and F6 not working

Hi!

the f1 and f6 buttons are not working properly since this morning.
i have to press them several times (up to twenty! lol) or hold them
down a few seconds to make them execute the operation.
so they still work, but do not cooperate very well.

i reinstalled the operating system, did a factory reset, took
out the ram expansion, pressed every button to check if one is locked.
nothing helped.

i just want to ask before i send it in, if anyone has a clue what this
could be. anyone maybe had a similar problem (with any other gear) and opened it and there was a loose connection or something?

thanks
tim

I had a similar problem, but with the "mode" button......It was due to overheating. When I put it an air conditioned room it worked fine.