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geekhack Projects => Making Stuff Together! => DIY Discussions ARCHIVE => Topic started by: CeeSA on Wed, 05 January 2011, 12:00:21

Title: Cherry G80 3000 - Controller, blue wire?
Post by: CeeSA on Wed, 05 January 2011, 12:00:21
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?

(http://geekhack.org/attachment.php?attachmentid=14541&stc=1&d=1294250276)
(http://geekhack.org/attachment.php?attachmentid=14542&stc=1&d=1294250276)
Title: Cherry G80 3000 - Controller, blue wire?
Post by: sixty on Wed, 05 January 2011, 17:15:53
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.
Title: Cherry G80 3000 - Controller, blue wire?
Post by: woody on Wed, 05 January 2011, 17:19:10
The ground plane on the PCB makes a shield so it causes much less EMI (http://www.youtube.com/watch?v=kjbie1O1jxc), and is also less disturbed by such.
Title: Cherry G80 3000 - Controller, blue wire?
Post by: CeeSA on Fri, 07 January 2011, 12:58:59
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
Title: Cherry G80 3000 - Controller, blue wire?
Post by: ricercar on Fri, 07 January 2011, 14:51:24
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.
Title: Cherry G80 3000 - Controller, blue wire?
Post by: woody on Fri, 07 January 2011, 14:55:11
CeeSa, get a cheapo multimeter and save yourself some trouble.
Title: Cherry G80 3000 - Controller, blue wire?
Post by: CeeSA on Fri, 07 January 2011, 16:57:13
@ 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"?
Title: Cherry G80 3000 - Controller, blue wire?
Post by: woody on Sat, 08 January 2011, 06:35:27
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.
Title: Cherry G80 3000 - Controller, blue wire?
Post by: hasu on Sat, 08 January 2011, 23:16:43
Quote from: ricercar;274760
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.
Title: Cherry G80 3000 - Controller, blue wire?
Post by: lowpoly on Sun, 09 January 2011, 04:11:37
Quote from: woody;273685
The ground plane on the PCB makes a shield so it causes much less EMI (http://www.youtube.com/watch?v=kjbie1O1jxc), and is also less disturbed by such.

This.

Try desoldering it. The keyboard will still work.
Title: Cherry G80 3000 - Controller, blue wire?
Post by: CeeSA on Sun, 09 January 2011, 08:33:33
ok blue is for ground and the keyboard works without ground.

here are some pics of my testing and progress

(http://geekhack.org/attachment.php?attachmentid=14633&stc=1&d=1294583750)
(http://geekhack.org/attachment.php?attachmentid=14634&stc=1&d=1294583750)
(http://geekhack.org/attachment.php?attachmentid=14635&stc=1&d=1294583750)
(http://geekhack.org/attachment.php?attachmentid=14636&stc=1&d=1294583750)

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

i have to check my points.

thanks for helping me!