ZX81 keyboard repair (ribbon replacement)

[zx80nut]

I repaired one of my ZX81's several years ago, and it is still working perfectly, despite having been taken apart many times.

The keyboard had stopped working due to a cracked connector cable.

Here is how I repaired it...

http://zx80.netai.net/zx81/ZX81KBRepair.htm

...not under my usual Web domain, as I have run out of space on there (only a very small domain provided by BT Internet!)
Still in draft, needs a bit more text, but I think you can see what I did.

I also did a similar repair to my QL, and that was about 10 years ago, and still works.

Regards.

Grant.

[iturbez]

Very interesting...
Good job!

[Andy Rea]

Cool, i remeber doing a very similar thing many many years ago... when ZX81's were in fashion.... and i was about 12 or 13.

But yeah i'm gonna hve to do this with one of my keyboards it's been trimmed more than once to the point that it no longer reaches !

Andy

[sirmorris]

Clever stuff!

[RWAP]

The lengths people will go to to save buying a replacement membrane

Actually, the downside is that you may need to remove the molex connectors (or use a PCB which forces them too wide for a keyboard membrane). Luckily I have just bought some more molex connectors, as I was down to my last 2 sets!

[zx80nut]

Hi Rich.
The plug that I made from old chip pins ensures the molex connectors are not pushed open any further than if they had the membrane inserted, so they are still usable if a new membrane is needed at a later date.
By attaching a connector at the top of the case, the remaining membrane remains flat, so is unlikely to crack in future (as the existing ones always break at the bends).

Grant

[prolog]

Far Out! This will work for extrnal KBs just as well presumably? I understand that we can no longer get the membrane type ribbon -
Jeff

[1024MAK]

I repaired one of my ZX81's several years ago, and it is still working perfectly, despite having been taken apart many times.
The keyboard had stopped working due to a cracked connector cable.
Here is how I repaired it...http://zx80.netai.net/zx81/ZX81KBRepair.htm
Regards.
Grant.

Now where is that like
button to

Mark

[Prime]

The lengths people will go to to save buying a replacement membrane

Well to be fair I did something similar (de-soldered the molex connectors from the board and put them on lengths of ribbon cable, plugged into shortened membrain cable). However this was *BEFORE* the ZX81 membrains where available, so there was really no other option Same prolly goes for Grant too....

Actually, the downside is that you may need to remove the molex connectors (or use a PCB which forces them too wide for a keyboard membrane). Luckily I have just bought some more molex connectors, as I was down to my last 2 sets!

Which is why I did what I did and put the ribbon between the molex and the board, as when I was able to replace the membrain, all I had to do was remove the ribbon cable and re-solder the molex connectors back to the 81 motherboard.

Cheers.

Phill.

[Moggy]

The lengths people will go to to save buying a replacement membrane

Well to be fair I did something similar (de-soldered the molex connectors from the board and put them on lengths of ribbon cable, plugged into shortened membrain cable). However this was *BEFORE* the ZX81 membrains where available, so there was really no other option Same prolly goes for Grant too....

Actually, the downside is that you may need to remove the molex connectors (or use a PCB which forces them too wide for a keyboard membrane). Luckily I have just bought some more molex connectors, as I was down to my last 2 sets!

Which is why I did what I did and put the ribbon between the molex and the board, as when I was able to replace the membrain, all I had to do was remove the ribbon cable and re-solder the molex connectors back to the 81 motherboard.

Cheers.

Phill.

First repair I ever did on an issue three was just as described above.



Moggy