Repairing M0487 keyboard advice

A few keys are not working on my mac M0487 keyboard, I’ve dismantled and can‘t get any contact between the relevant points on the keyboard membrane. Any advice on a fix? Thanks

I have fixed these membranes using stuff called 'bare conductive electric paint'

its just a small tube of black gooey stuff

you find the break in the trace on the membrane , put down some masking tape either side of the trace , and basically paint a tiny amount of the stuff over where you think the break is

then you have to wait about 2 hours for it to dry / cure. When dry it is not brittle , has a bit of give in it

only then does it become conductive - but it worked for me

here - found it for ya on ebay - this is what i used

https://www.ebay.ie/itm/142854993347?hash=item2142d235c3:g:b4AAAOSwgw9bPgCL&amdata=enc:AQAIAAAAwBYkoofGFxXj60KrhdIeDUKcxREIkuhI2BFfwsnZoV1r9EXH2AM0t0M/i3LBTxgayDDFwvjjIB+DU3nCfG0uklo8BHTK1mIUv0qQF/JwcHgWrZkVTa5uETGVsgaRhIvX8t3O/i91MJdaT0gUIzZHnMeB8/SMXzP5qnUSWmSTy+IBy9XQShKkVxLms7zdUwj9T1atCBIDEegdjnNxLk7WgBJvYT2Eld605k/9G9oc1xFXPi7EB/0tD8D+w1VXNX8Y+w==|tkp:Bk9SR_i-m9mTYg

That’s great thanks falen6, I’ll have a look at the traces, cheers!

Can't find a schematic for this anywhere, going to use this image to help follow the traces, might be useful for others:

you dont need a schematic

you know what keys dont work
you see where they are in the membrane
you see the 2 contacts for the switch
put your continutity test from the start of the ribbon cable to the black contacts of the actual switch - the black contact surface will give you goos contact

when you have 1 key not working , it usually has a few more keys not working with it - when you start tracing out the matrix of the membrane yo see that a single trace from the ribbon connector partly controls 3 or 4 keys

when you find that on the same trace one key works but the next on the same trace does not then you are getting close to the break in the trace


when you find the break you have to scrape off the laquere that they sprayed on the traces to expose the trace itself - with should be able to see the actual break in the trace - thats where you paint your black goo !!

but remember to leave it for a few hours to cure - the stuff is not conductive until it cures


in most cases for the ones i fixed there was always damage in the membrane ........ a puncture in it as if some one lost the head and stabbed the keyboard

some had folded or trapped membranes as if someone had opened it in the past and put it back together asre ways

but once you fix one trace your laughing - the rest is easy

Nice one, thanks Falen, yes that’s my plan and figured there’s a few in the same area (space bar, arrow keys…) just going to use the schematic to plan out the connections make it a bit easier to see whats going on

Hi,

I have a single key (dot on the numeric pad) on my M0487 keyboard that doesn't work. I cleaned the keys and membrane but that didn't fix the issue.
I found a similar conductive paint here and some images of the inside of the keyboard: Apple Keyboard II

Is it fairly easy to open i.e. I can see 2 screws so once they're removed, do I need to unclip something ?
I understand that I need to clean the membrane, spot any broken wire, apply the paint, and let it drive.

Pretty simple as I recall, this is helpful . then just follow Fallen6 method above. The breaks can be very very small.

Thanks for the video !

Hi,
A simple clean of the membrane did the job. I didn't have to use the conductive paint.