English Amiga Board - View Single Post - [Absolute last resort] Solution to A600 (maybe 1200?) keyboard cable problem

Ferry · 27 July 2018, 03:38

Well, I received my new A1200 keyboard membrane just yesterday, and today I had the time to try my crazy experiment.

I bought it advised by another Amiga user and friend, Fireboy, that also bought a membrane for his Vampirized A600. But since he's always trying new hardware, his keyboard is detached and reattached every now and then, and his keyboard connector got worn out very quickly. Of course I didn't want mine to happen the same, so I thought about a possible solution: to use aluminium foil to cover connector pins, so it's the aluminium that receives the pressure and the wear-out, not the connector. Aluminium is so tough that it would be possible that the wear-out would never prevent the keyboard to function, and in any case you could always replace the covering.

The domestic one, even if it is conductive, doesn't work because there's no (cheap) way to stick it on, but there's one alternative: the adhesive aluminium foil in rolls used in air conditioner installations.

The problem with this one is that while one of the sides is conductive, the adhesive one is not, but is very easy to rub the adhesive away with alcohol (preferably isopropyl).

So I have tried today, and IT WORKS!

If you want to try it too, you will need:

-Roll of adhesive aluminium foil, 5 cm wide
-Watchmaker tweezers
-Watchmaker magnifying glass or lamp with magnifying glass (I used something like this one: https://i.imgur.com/QjchY2L.jpg)
-Scissors
-Preferably, paper cutter. I used this kind: https://i.imgur.com/HNJMZ1j.jpg, the better the easier.
-Alcohol, preferably isopropyl (no residues)
-Cotton buds
-Multimeter
-Patience…

1. Cut a square piece of aluminium foil wider than the keyboard ribbon.

2. Cut the back paper at the middle of the piece, so a strip of 6 mm wide of the adhesive side gets exposed:

3. Rub the exposed adhesive with a cotton bud soaked in alcohol. You'll notice you are taking the adhesive out because the color will change from matte to brilliant:

4. Cover again the rubbed area with the white back.

5. Cut strips like 0'8 mm wide, with the rubbed part in the middle. You will need 31 strips, but cut some more, just in case.

6. Start sticking strips in place, connector by connector, starting in the back of the KB ribbon and adjusting the start of the rubbed part with the end of the ribbon, so when you turn it around the rubbed part covers the connector pin. Double check that one strip does not touch the previous one.

(NOTE: I have found that you can flatten a strip out, make them smoother by running a nail over it)

7. One thing you MUST CHECK with the multimeter is that two contiguous strips don't make contact, and you must check ALL STRIPS for this.

8. You can also check if the aluminium cover really works: follow the track of the contact you just covered with aluminium and find the first key contact in the keyboard corresponding to that track, and check continuity with the multimeter:

Of course, to follow every single track for 31 connectors is a really painstaking work, so you can check only some of them, f.ex., the ones that have their corresponding key connectors near.

9. Once finished, the ribbon should look something like this:

Back:

Front:

Of course, with a better paper cutter the strips would have been more even, more uniform.

10. Put the membrane back in place inside the keyboard (of course if, like me, you have been working on the membrane itself.)

11. Connecting the KB back to the motherboard: insert the ribbon into the connector latch.

12. Insert the ribbon into the motherboard connector itself. It should slide smoothly into it, despite being a bit thicker.

13. Close the latch. Here you will notice the extra thickness, you will have to apply a bit more pressure than usual.

Done!

One more advantage is that if one strip gets broken, whatever the reason, it should be easily replaceable.

Well, I have my new membrane protected, my keyboard working and I cannot imagine any drawback with this method that could hurt the membrane or harm in any way the computer. If you know any, just share it.

I hope you find this useful.

Saluditos,

Ferrán.

PD: I've put this post also as an independent new post in the support.Hardware forum.

27 July 2018, 03:38	#121
Ferry Registered User Join Date: Jul 2018 Location: Spain Posts: 106	Well, I received my new A1200 keyboard membrane just yesterday, and today I had the time to try my crazy experiment. I bought it advised by another Amiga user and friend, Fireboy, that also bought a membrane for his Vampirized A600. But since he's always trying new hardware, his keyboard is detached and reattached every now and then, and his keyboard connector got worn out very quickly. Of course I didn't want mine to happen the same, so I thought about a possible solution: to use aluminium foil to cover connector pins, so it's the aluminium that receives the pressure and the wear-out, not the connector. Aluminium is so tough that it would be possible that the wear-out would never prevent the keyboard to function, and in any case you could always replace the covering. The domestic one, even if it is conductive, doesn't work because there's no (cheap) way to stick it on, but there's one alternative: the adhesive aluminium foil in rolls used in air conditioner installations. The problem with this one is that while one of the sides is conductive, the adhesive one is not, but is very easy to rub the adhesive away with alcohol (preferably isopropyl). So I have tried today, and IT WORKS! If you want to try it too, you will need: -Roll of adhesive aluminium foil, 5 cm wide -Watchmaker tweezers -Watchmaker magnifying glass or lamp with magnifying glass (I used something like this one: https://i.imgur.com/QjchY2L.jpg) -Scissors -Preferably, paper cutter. I used this kind: https://i.imgur.com/HNJMZ1j.jpg, the better the easier. -Alcohol, preferably isopropyl (no residues) -Cotton buds -Multimeter -Patience… 1. Cut a square piece of aluminium foil wider than the keyboard ribbon. 2. Cut the back paper at the middle of the piece, so a strip of 6 mm wide of the adhesive side gets exposed: 3. Rub the exposed adhesive with a cotton bud soaked in alcohol. You'll notice you are taking the adhesive out because the color will change from matte to brilliant: 4. Cover again the rubbed area with the white back. 5. Cut strips like 0'8 mm wide, with the rubbed part in the middle. You will need 31 strips, but cut some more, just in case. 6. Start sticking strips in place, connector by connector, starting in the back of the KB ribbon and adjusting the start of the rubbed part with the end of the ribbon, so when you turn it around the rubbed part covers the connector pin. Double check that one strip does not touch the previous one. (NOTE: I have found that you can flatten a strip out, make them smoother by running a nail over it) 7. One thing you MUST CHECK with the multimeter is that two contiguous strips don't make contact, and you must check ALL STRIPS for this. 8. You can also check if the aluminium cover really works: follow the track of the contact you just covered with aluminium and find the first key contact in the keyboard corresponding to that track, and check continuity with the multimeter: Of course, to follow every single track for 31 connectors is a really painstaking work, so you can check only some of them, f.ex., the ones that have their corresponding key connectors near. 9. Once finished, the ribbon should look something like this: Back: Front: Of course, with a better paper cutter the strips would have been more even, more uniform. 10. Put the membrane back in place inside the keyboard (of course if, like me, you have been working on the membrane itself.) 11. Connecting the KB back to the motherboard: insert the ribbon into the connector latch. 12. Insert the ribbon into the motherboard connector itself. It should slide smoothly into it, despite being a bit thicker. 13. Close the latch. Here you will notice the extra thickness, you will have to apply a bit more pressure than usual. Done! One more advantage is that if one strip gets broken, whatever the reason, it should be easily replaceable. Well, I have my new membrane protected, my keyboard working and I cannot imagine any drawback with this method that could hurt the membrane or harm in any way the computer. If you know any, just share it. I hope you find this useful. Saluditos, Ferrán. PD: I've put this post also as an independent new post in the support.Hardware forum. Last edited by Ferry; 27 July 2018 at 03:51.