128D RETURN key does not work

[leofoe]

Today I got a Commodore 128D computer. It works, but has one nasty problem: the RETURN keys do not work. I opended the case to reseat all chips to no avail. Opening the keyboard also did not expose any problems. Because both RETURN keys do not work I think the problem is not in the keyboard itself.
Hope someone can shed some light...

[leofoe]

Both Return keys do not work in any mode.

[leofoe]

redrumloa wrote:
Well that sucks! HERE is a start..

Thanks. I came across that nice description also.
Because both keys do not work, I don't think the problem is in the keyboard. But I will dismantle it completely if there is a good change the problem is in there after all.

[leofoe]

What I discovered so far is that on the dismantled keyboard, there is a shortcut between the most left and most right wire. I think these are pins 1 and 25 on the Centronics connector.

EDIT: Sorry, it's pin 1 and 24 on the Centronics connector. The wires on the keyboard are brown and purple-white. Can anybody confirm that these wires should shortcut?

EDIT 2:
Keyboard schematic

[leofoe]

I got the RETURN-key working by reseating VIC U21. ENTER-key still a no go.