Hello,
My middle row of keys from caps lock to @ have stopped working.
Also the caps lock light is not working.
All the other keys work fine.

@electric-magic

Is this something that's happened suddenly?

@Rob

Yes.
It was working fine on Saturday.

@electric-magic

Has it been dropped or anything that might have caused stress to the cable or membrane. I think the most obvious possible problem is a fracture in the wire somewhere.

@Rob

No, not been dropped or anything.
I suppose the first thing I should do is try another keyboard. Problem being I don't have another one.

@electric-magic

Have you got a multimeter or know someone who has. You can at least test the wiring connector for continuity. I do have a spare keyboard here but it's a bit far for the sake of a test.

@Rob

I will go buy a multimeter in the morning and check the cable.

Thanks.

@electric-magic

Make sue the multimeter has continuity test function. Somehow I managed to buy one without it by assuming that it would be one of the most basic functions included.

@Rob



Have a local machine mart round the corner. Picked up a multimeter for a tenner.

Have done a test and the wires all have continuity EXCEPT pin 1 using the image from the above website.
Pin 1 is data.

What do you think?

@electric-magic

Must be break in the wire somewhere then. If you have an old PS2 keyboard somewhere you could cannibalise that in order to knock up a replacement cable for testing.

@Rob

Thanks for your help. I will get in the loft in the morning for a PC keyboard.

John.

@electric-magic

I hope it's successful.

@electric-magic

Did you get the keyboard fully working?

@Rob

Sorry Rob, had the family down for a few day's.
I will let you know.

Had another thought though. The a4000 keyboard fits the CD32.
I think I will plug it in and see if I have the same problem and this should confirm if is is the keyboard.

@electric-magic

To be honest it's very unlikely that the cable is the fault if some of the keys are working. The keyboard works with a single data line - all keys use that one line, so if it had a problem, all keys would be affected instead of one particular row. Keyboards use a matrix of contacts with common rows and columns all connected to the keyboard controller chip - my bet is that the centre row common has been damaged somehow - perhaps by old age. Take it apart and check the keyboard controller chip for dry or cracked solder joints, and check the keyboard membrane itself. A multimeter will help greatly here!

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@Daedalus

I think you might be right.
I have re-wired a new cable to the keyboard but having the same problem.
I have checked the keyboard controller and it looks fine.
How do I check the membrane?

Just a quick hijack.

Does anyone know if caps lock lights up if there is no cpu card plugged inside a A4000 (or cpu card is defective)? Or is it that caps lock light stopped working?

@Ancalimon

The keyboard needs to be in sync with the computer before it will do a self-test (single blink normally), and allow the caps lock key to work. So without a CPU to initialise the hardware I doubt you'll get any sign of life from the keyboard.

I have come across a couple of Amiga keyboards with faulty LEDs, but usually cleaning the pads and LED legs was enough to get them working again.

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RobTheNerd.com | InstallerGen | SMBMounter | Atoms-X

@electric-magic

You'll have to check each of the relevant lines with a multimeter to see if there's a break. Since a whole section of the keyboard is dead, check for a common trace that is used for them all, and check this all the way back to the controller. This I'd most likely where the fault lies, but it can be tricky to spot visually, and repairing membranes is a nasty job too...

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