Keyboard fault on A1200

[Tricky]

Hello, I'm having a spot of bother with the keyboard on one of my A1200s.  It seems an entire column of keys has stopped working, at first it was just Y, and then N, but now none of 6, Y, H or N work, and also the 8 on the numeric keypad.

I've taken the keyboard apart.  The board itself looks absolutely fine, there's nothing obviously wrong with the carbon contacts.  I've tried using the rubber contact from one of the other keys to stimulate the broken ones but that doesn't work either, so it's definitely something on the board and not the actual keys.

It's as if one of the tracks has broken, but why didn't all the keys go at once?  More importantly, is there anything I can do about it other than find a replacement keyboard?

Any help appreciated.
Thanks

[paranha]

Have you checked the cable that goes down to the motherboard?.

I opened up my 1200 and "accidentaly" touched that cable. Nooo keyboard working and felt quite stupid about it since i recently bought it. Checked the cable and it was actually out of position in the socket. repositioned  it but didn't work. I cleansed the cable for oxidizing on the contact surface and got it to work again.

Maybe that's worth checking?

[rkauer]

If u have a died A500 around, simply use this hack :rtfm:

[amigakid]

Reset your ribbon cable on the motherboard and the keyboard.  This can be a possible cause.  Make sure that the cable is firmly and securely seated.

[Tricky]

rkauer wrote:
If u have a died A500 around, simply use this hack :rtfm:

hehe we've got two!
One of the other A1200s has its disk drive from one of them.  It wasn't an easy job getting it to fit and involved a certain amount of cardboard.

[Tricky]

paranha wrote:
Have you checked the cable that goes down to the motherboard?.

I've had a look, the contacts are a bit brown.  It's obviously been taken out before because the little plastic bit that holds the ribbon down is a bit chewed looking and one of the sides is broken off.  Will try cleaning it once we work out what is safe to put on it... we've got Turpentine substitute, white spirit and nail polish remover.

[paranha]

Tricky wrote:

paranha wrote:
Have you checked the cable that goes down to the motherboard?.

I've had a look, the contacts are a bit brown.  It's obviously been taken out before because the little plastic bit that holds the ribbon down is a bit chewed looking and one of the sides is broken off.  Will try cleaning it once we work out what is safe to put on it... we've got Turpentine substitute, white spirit and nail polish remover.

Stay away from the white spirit. That stuff is full of fat and i don't know how the insulation on the cable will handle that. It's the same with turpentine.

Nail polish remover or regular alcohol and a couple of
Q-tips (ear cleaners) for the rubbing on those surfaces. Start with the product that is weakest

[Brian]

It's quite comon that if a track on the green cable going to the motherboard doesn't have a connection a row of keys will stop working. The plastic that press onto the cable should be stright (there need to be a pressuear all the way over the cablecontact) and make sure the carbon contact of the cable is not damaged (easily happens if you remove the cable impropperly and then sometimes it can help to cut off a few mm of the cable as the carboncontact area is almost twice as long as is nessesary so a fresh patch of the carbon on the cable gets contact).

[Zac67]

Tricky wrote:
we've got Turpentine substitute, white spirit and nail polish remover.

Nail polish remover (acetone) actually dissolves plastics. Stay away from the rest as well and get some pure alcohol to clean the contacts.

[Tricky]

Zac67 wrote:

Nail polish remover (acetone) actually dissolves plastics. Stay away from the rest as well and get some pure alcohol to clean the contacts.

That's what I thought.  I fixed it now anyway.  An internet told me you can clean contacts with a white eraser.  Well I tried that, and that didn't work.  Then I thought I'd just gently brush the surface with an emery board, and ended up scraping some of the tracks off.  Oops.

So in the end I peeled a bit of the plastic off the ribbon and cut the end off.  That worked.

I hope it stays working though as there's obviously a limit to how many times you can do that.

[jimbob005]

i have a 1200 keyboard here if you want it .
as long as you pay the p&p its yours.
its a bit yellow but you can swop the keys if you want .

thanks james