G3 Imac Mac Pro Keyboard (m7803) Circuit Membrane Cleaning Help

bare spots

macrumors member
Original poster
Dec 31, 2007
59
7
northeast
The g3 is gone for quite a while but they left behind the keyboard. Btw-not sure where to ask this, thought this good as any, if in a bad spot not in up to forum decorum, mods can u please correct. On the keyboard, long story short, am in need of a Mac KB atm and am waiting on a new one (new one ordered and being ship) btw but am a little impatient not to mention got the time along with figuring got nothing to loose so decided to mess around with the one that's here, maybe if cleaned it up somewhat, never know. If anything, was curious how it ticked, and need one asap.. So anyways, got pretty all apart, keys, covers, board etc cleaned up, all for the circuity part or circuit membrane part (not sure correct name part atm, film sheets, 2 ofthem) I put messing with that on hold for now as not sure best way or if even possible, as looking at it it look pretty dirty and since came this far and effort put in so far, might as well see this through. Like said short of finding a replacement part (maybe there's a stack of them somewhere), trying to figure best way forward in an attempt in cleaning these up. Before I go, got electrical cleaner here or some kind of mixture w/distilled water etc. Leading towards electric cleaner. ty
 

amagichnich

macrumors 6502
Feb 3, 2017
468
272
Stuttgart, Germany
If there is an actual question in that block of text, it would help if you'd highlight it with the magic "?" sign.
Right now I don't understand what your problem or question is
 

AphoticD

macrumors 68000
Feb 17, 2017
1,761
2,214
Australia
The g3 is gone for quite a while but they left behind the keyboard. Btw-not sure where to ask this, thought this good as any, if in a bad spot not in up to forum decorum, mods can u please correct. On the keyboard, long story short, am in need of a Mac KB atm and am waiting on a new one (new one ordered and being ship) btw but am a little impatient not to mention got the time along with figuring got nothing to loose so decided to mess around with the one that's here, maybe if cleaned it up somewhat, never know. If anything, was curious how it ticked, and need one asap.. So anyways, got pretty all apart, keys, covers, board etc cleaned up, all for the circuity part or circuit membrane part (not sure correct name part atm, film sheets, 2 ofthem) I put messing with that on hold for now as not sure best way or if even possible, as looking at it it look pretty dirty and since came this far and effort put in so far, might as well see this through. Like said short of finding a replacement part (maybe there's a stack of them somewhere), trying to figure best way forward in an attempt in cleaning these up. Before I go, got electrical cleaner here or some kind of mixture w/distilled water etc. Leading towards electric cleaner. ty
It is sometimes possible to resurrect a liquid damaged keyboard by cleaning the two clear printed circuit sheets. I would use Isopropyl Alcohol (99.8%) to clean the contacts on these sheets. It's not always fixable, but could be worth a try.
 
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bare spots

macrumors member
Original poster
Dec 31, 2007
59
7
northeast
It is sometimes possible to resurrect a liquid damaged keyboard by cleaning the two clear printed circuit sheets. I would use Isopropyl Alcohol (99.8%) to clean the contacts on these sheets. It's not always fixable, but could be worth a try.
Thanks, did a little research last night. Saw that on the ipa, one method mentioned ultra sonic cleaner machine I believe of some sort. IPA might the wise choice for this project being it's on hand. The board (PCB) looks to be in rough shape, not sure how it got in there but some dirt or grime is physically bonded, right on circut links. Plus haven't looked for broken circuits, which I' m curious to playing around with to see how they work but pretty there are plenty, at least to my understanding how this functions. So Im thinking it's pretty well shot, but well see, if anything I'll be out some time, thanks
 

bare spots

macrumors member
Original poster
Dec 31, 2007
59
7
northeast
Sorry on my first post BTW, posted from a tablet, got a little flustered as my tablet has been crashing last few times have been posting for some reason, mid post. (Not a Mac, my next one gonna be but did a reset, so far so good). ! For my post, just wanted to see any thoughts etc. in dealing with cleaning etc circut membranes in keyboard. As of this eve. though, got everything I need and good to go, thanks
 

bare spots

macrumors member
Original poster
Dec 31, 2007
59
7
northeast
Just a follow-up to where at at from attempt at cleaning the PCB. I the IPA mentions last night and it did a pretty good job, had some debris bonded in an area, some persistence paid off. My research in cleaning, found ways of checking circuits w/no electronic whiz here but looks like this boards not completing the circut. Been trying to learn about this stuff, looks like maybe on to a next step, an a repair attempt.
[doublepost=1548703299][/doublepost]Just a quick note, then move on from my ramblings of my keyboard issue. And that I get the idea of how these PCB membranes keyboards work. Press the key and it completes the circuit but looking at it, not quite understanding how this capital key works. Don't remember when took the keys off it it had a lock mechanism, if it did hope I didn't mess it up.
 
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