Keyboard Mapping Issue Sony HB-F5

By jacco_bot

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02-07-2020, 23:20

Hello, I'm experiencing an odd issue with my recently purchased HB-F5. The machine is as new, hasn't got a scratch and looks like it has been stored in it's box for a long time.
The machine works, runs all the cartridges I have thrown at it, everything checks out... except:

All the keys that are not alpha-numeric are not producing the character on screen that one would expect. For instance, the semi-colon key produces the "`" symbol, the ","- key produces the "+" symbol, as if some wires have crossed.

First thing I did was check all the keyboard connectors, solder points and checked that everything is connected correctly. The odd thing is, that repeated key strokes will occasionally produce the correct key, seemingly randomly the correct stroke appears on screen.

None of the numeric and alpha-numeric keys are affected, just the keys right of the 0, P, L, and M. Backspace, return, shift, graph etc all work correctly.

I'm wondering if anyone has experienced this phenomenon and if they were able to solve it. I am wondering if this could be a problem in the key-scan logic, or the timing there-of.

Anyway, any insight or thoughts on the matter would be greatly appreciated!

Jacco.

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By jacco_bot

Supporter (10)

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03-07-2020, 04:00

Well, nevermind... After using the HB-F5 for an hour or so, the problem became less. The keys would still be read wrong, but more frequently the right characters would appear. Another hour or so and the issue became less frequent. Suspecting that maybe the heat from the components expanded some pins or connections, I turned the computer off and let it completely cool down. Upon turning it back on, the issue has completely disappeared. Almost like a squeaky wheel in a machine, except that electronics usually don't behave this way.
Anyway, I now have a beautiful HB-F5 in perfect working order. The motherboard is so clean it looks like it came straight out of the factory, no wear on the keyboard or case whatsoever, not even a spot where hands would have touched it. Truly a gem.