Poster | Thread |
electric-magic
| |
A4000 keyboard only part working Posted on 25-Aug-2014 14:30:01
| | [ #1 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| 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.
|
|
Status: Offline |
|
|
Rob
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 14:46:46
| | [ #2 ] |
|
|
|
Elite Member |
Joined: 20-Mar-2003 Posts: 6351
From: S.Wales | | |
|
| @electric-magic
Is this something that's happened suddenly? |
|
Status: Offline |
|
|
electric-magic
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 15:03:14
| | [ #3 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| @Rob
Yes. It was working fine on Saturday.
|
|
Status: Offline |
|
|
Rob
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 16:00:13
| | [ #4 ] |
|
|
|
Elite Member |
Joined: 20-Mar-2003 Posts: 6351
From: S.Wales | | |
|
| @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. |
|
Status: Offline |
|
|
electric-magic
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 16:08:11
| | [ #5 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| @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.
|
|
Status: Offline |
|
|
Rob
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 16:15:37
| | [ #6 ] |
|
|
|
Elite Member |
Joined: 20-Mar-2003 Posts: 6351
From: S.Wales | | |
|
| @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. |
|
Status: Offline |
|
|
electric-magic
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 16:19:18
| | [ #7 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| @Rob
I will go buy a multimeter in the morning and check the cable.
Thanks. |
|
Status: Offline |
|
|
Rob
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 16:25:50
| | [ #8 ] |
|
|
|
Elite Member |
Joined: 20-Mar-2003 Posts: 6351
From: S.Wales | | |
|
| @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. |
|
Status: Offline |
|
|
electric-magic
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 17:21:51
| | [ #9 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| @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?
|
|
Status: Offline |
|
|
Rob
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 17:41:16
| | [ #10 ] |
|
|
|
Elite Member |
Joined: 20-Mar-2003 Posts: 6351
From: S.Wales | | |
|
| @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. |
|
Status: Offline |
|
|
electric-magic
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 17:54:03
| | [ #11 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| @Rob
Thanks for your help. I will get in the loft in the morning for a PC keyboard.
John. |
|
Status: Offline |
|
|
Rob
| |
Re: A4000 keyboard only part working Posted on 25-Aug-2014 18:32:22
| | [ #12 ] |
|
|
|
Elite Member |
Joined: 20-Mar-2003 Posts: 6351
From: S.Wales | | |
|
| @electric-magic
I hope it's successful. |
|
Status: Offline |
|
|
Rob
| |
Re: A4000 keyboard only part working Posted on 28-Aug-2014 14:14:19
| | [ #13 ] |
|
|
|
Elite Member |
Joined: 20-Mar-2003 Posts: 6351
From: S.Wales | | |
|
| @electric-magic
Did you get the keyboard fully working?
|
|
Status: Offline |
|
|
electric-magic
| |
Re: A4000 keyboard only part working Posted on 28-Aug-2014 14:25:08
| | [ #14 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| @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. |
|
Status: Offline |
|
|
Daedalus
| |
Re: A4000 keyboard only part working Posted on 28-Aug-2014 22:23:49
| | [ #15 ] |
|
|
|
Super Member |
Joined: 14-Jul-2003 Posts: 1680
From: Glasgow - UK, Irish born | | |
|
| @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! _________________ RobTheNerd.com | InstallerGen | SMBMounter | Atoms-X |
|
Status: Offline |
|
|
electric-magic
| |
Re: A4000 keyboard only part working Posted on 1-Sep-2014 10:00:27
| | [ #16 ] |
|
|
|
Member |
Joined: 10-Feb-2013 Posts: 44
From: Paphos, Cyprus | | |
|
| @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?
|
|
Status: Offline |
|
|
Ancalimon
| |
Re: A4000 keyboard only part working Posted on 1-Sep-2014 10:42:53
| | [ #17 ] |
|
|
|
Regular Member |
Joined: 23-Mar-2004 Posts: 433
From: Istanbul | | |
|
| 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? |
|
Status: Offline |
|
|
Daedalus
| |
Re: A4000 keyboard only part working Posted on 1-Sep-2014 12:19:38
| | [ #18 ] |
|
|
|
Super Member |
Joined: 14-Jul-2003 Posts: 1680
From: Glasgow - UK, Irish born | | |
|
| @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. _________________ RobTheNerd.com | InstallerGen | SMBMounter | Atoms-X |
|
Status: Offline |
|
|
Daedalus
| |
Re: A4000 keyboard only part working Posted on 1-Sep-2014 12:33:27
| | [ #19 ] |
|
|
|
Super Member |
Joined: 14-Jul-2003 Posts: 1680
From: Glasgow - UK, Irish born | | |
|
| @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... _________________ RobTheNerd.com | InstallerGen | SMBMounter | Atoms-X |
|
Status: Offline |
|
|