Dead keys on Atari Portfolio

[Uityyy]

I have an Atari Portfolio that powers on but has only some of they keys work.
When I tested earlier tonight the following keys were dead:
1 2 0 - q i [ ] LOCK J ' CTRL SHIFT UP
So I decided to take the machine apart and clean it with 91% isopropyl alcohol.
I got the machine back together, and it still runs, but now more keys rather than fewer refuse to work.

Is there a secret to maintaining these membrane(?) keyboards?

 

[Retroplayer]

I have one on the way, but have not owned one previously. It is possible that your cleaning removed the carbon from the keys? If so, you will need to replace it.

There used to be pens for repairing remotes, but I am not finding them now for some reason. However, there are conductive ink pens that might work.

 

[Retroplayer]

File:Atari Portfolio HPC-004 - display part - board - Philips PCD3311T-4659.jpg - Wikimedia Commons

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