Cherry G80 3000 - Controller, blue wire?

[CeeSA]

i have a question around the cherry controller.
there is a big blue wire from the controller to the pcb.
is that for "earthing" / ground?
for what a the 2 pins "J1" second image?

when i cut off the whole part with the controller and solder all new,
is earthing necessary?

have you any suggestion for earthing / ground?

[sixty]

Yes, that big cable should be ground.
The two pins seem to be a bridge for ground.

With most keyboards I have seen, the ground usually ends on a dead point in the PCB (like with your Cherry) or directly on a longer thick cable into the plsatic case.

[woody]

The ground plane on the PCB makes a shield so it causes much less EMI, and is also less disturbed by such.

[CeeSA]

hmm, now i think its not ground.
it's for 5V from usb to bring power to the pcb.
is there a way to bring the power to the pcb after i cut of the side with the controller and the power?

i need more help

[ricercar]

That wire is definitely NOT ground, neither here nor on my G80-6955, nor 82xx. It's positive voltage supply; Note the + symbol on the PCB next to the wire's connection in the OP picture.

[woody]

CeeSa, get a cheapo multimeter and save yourself some trouble.

[CeeSA]

@ woody - i own one, but he answers not my question:

is there a way to bring the power to the pcb after i cut of the side with the controller and the power?
i think i has to bring the 5V to PCB in the different "areas"?

[woody]

I am not sure I understand your question.

If you remove the controller board and the multimeter's continuity tester (beeper) shows that you have connection between some pin of the cable and the thick wire, then you can just ignore the wire for your experiments.

EDIT: And of course, if there's no connection - then you need to provide it via the wire. Multimeter will tell all.

[hasu]

That wire is definitely NOT ground, neither here nor on my G80-6955, nor 82xx. It's positive voltage supply; Note the + symbol on the PCB next to the wire's connection in the OP picture.

I have a G80-3600LYCEU whose controller board looks almost same as OP's.
I'm sure the blue wire is GND in my 3600 at least.
Its PCB routes told me enough, but I used my multimeter to confirm it

I think CeeSA still should use a multimeter to be sure.

[lowpoly]

The ground plane on the PCB makes a shield so it causes much less EMI, and is also less disturbed by such.

This.

Try desoldering it. The keyboard will still work.

[CeeSA]

ok blue is for ground and the keyboard works without ground.

here are some pics of my testing and progress






some keys works wrong, some keys does not work at all.

i have to check my points.

thanks for helping me!