Replace Amiga 1200 Caps Led

[RetroHut]

Hi All, Greetings from Aus


I'm repairing a Amiga 1200 no caps light issue have have discovered that the keyboard LED is totally missing along with the little black piece that holds it in (see Photo)


Whilst I have a replacement LED I don't have the replacement black holder piece. So my question is can I add some hot glue or similar instead? Anyone solved this differently?


Thanks in advance

Photo https://ibb.co/QdXzg7z

[Snoopy1234]

the rubber is conductive, separated by a plastic insulator in the middle. It conducts current from the membrane to the led pins. You'll definitely need one or something similar. Also the led's are polarized and don't work the other way round.

[RetroHut]

Originally Posted by Snoopy1234

the rubber is conductive, separated by a plastic insulator in the middle. It conducts current from the membrane to the led pins. You'll definitely need one or something similar. Also the led's are polarized and don't work the other way round.

Thanks Snoopy, I might have to get creative with the 3D printer and some remote control spare rubbers

[Boing-Ball]

Originally Posted by RetroHut

Thanks Snoopy, I might have to get creative with the 3D printer and some remote control spare rubbers

It’s a graphene conductive layer. You can use a rubber but it won’t be conductive.

Try using a conductive paint instead. Search EBay for it.

[RetroHut]

Thank you, does anyone have a photo and possible dimensions?

[Snoopy1234]

I think the A500 mitsumi keyboard would have the same component.... Can not confirm that though. Here's one. https://allegro.pl/oferta/amiga-500-...ck-12287711275

[mja65]

Originally Posted by Boing-Ball

It’s a graphene conductive layer. You can use a rubber but it won’t be conductive.

Try using a conductive paint instead. Search EBay for it.

Hi All

Also (coincidentally) greetings from Australia - looks like a few of us on this thread!

I have an Amiga 600 with the same missing part (confession time in that I stupidly lost mine down the kitchen sink!) so reading this thread with interest.

Excuse my ignorance, but how would I use the conductive paint? Is this as simple as cutting some non conductive rubber and painting all over it such that the painted rubber is touching both the membrane and the LED legs?

[Snoopy1234]

Originally Posted by mja65

Hi All

Also (coincidentally) greetings from Australia - looks like a few of us on this thread!

I have an Amiga 600 with the same missing part (confession time in that I stupidly lost mine down the kitchen sink!) so reading this thread with interest.

Excuse my ignorance, but how would I use the conductive paint? Is this as simple as cutting some non conductive rubber and painting all over it such that the painted rubber is touching both the membrane and the LED legs?

I'd think so but in two halves. each pin of the LED conducting to the corresponding contact point of the membrane. These must be seperated.

[RetroHut]

Originally Posted by mja65

Hi All

Also (coincidentally) greetings from Australia - looks like a few of us on this thread!

I have an Amiga 600 with the same missing part (confession time in that I stupidly lost mine down the kitchen sink!) so reading this thread with interest.

Excuse my ignorance, but how would I use the conductive paint? Is this as simple as cutting some non conductive rubber and painting all over it such that the painted rubber is touching both the membrane and the LED legs?

I actually just in the process of doing this with some silver trace repair paint (great minds). I'll be doing some testing today and post some pics ?

[mja65]

By all means please let me know how you got on! Btw (since you are also in Australia), where did you get the repair paint from? I had a quick look in Jaycar and the conductive paint I saw was $45! Ouch!

Originally Posted by RetroHut

I actually just in the process of doing this with some silver trace repair paint (great minds). I'll be doing some testing today and post some pics ?

[Boing-Ball]

Have a look on EBay for conductive paint. It’s used for circuit board repair on traces. Bought some in the U.K for roughly £6.

[RetroHut]

Originally Posted by mja65

By all means please let me know how you got on! Btw (since you are also in Australia), where did you get the repair paint from? I had a quick look in Jaycar and the conductive paint I saw was $45! Ouch!

No worry's I'm using this one. https://www.ebay.com.au/itm/14457094...mis&media=COPY

[mja65]

Thanks - I ended up going to Altronics where it was a little cheaper. In any case, I didn't need it. Some good old blue tack and some careful positioning seem to have done the trick!!

Originally Posted by RetroHut

No worry's I'm using this one. https://www.ebay.com.au/itm/14457094...mis&media=COPY

[Shaytan]

Originally Posted by mja65

Thanks - I ended up going to Altronics where it was a little cheaper. In any case, I didn't need it. Some good old blue tack and some careful positioning seem to have done the trick!!

Is blue tack conductive?

[mja65]

Nope - but it raised the legs sufficiently they make contact with the keyboard membrane.

Originally Posted by Shaytan

Is blue tack conductive?

[mja65]

Turns out I was a little premature and my solution was a little erratic. I bought a new LED and found the legs were a lot longer than the LED already installed which made it a lot easier to raise the legs to make contact with the membrane.

I had also bought some conductive paint. This didn't work at all. I think this was a combination both of the contact to the membrane as well as it was difficult to provide contacts both to the legs of the LED and whatever I attached to the legs. Not sure how others have got on?