I've added some pictures under "3561A repair" to document a problem with my SA. All the electronics check out after replacing some parts but some of the buttons and most of the LEDs were not working on the front panel. After opening the front panel I found that this conductive foam seems to be the culprit. I've repaired LCD displays by cleaning conductive foam but the conductors in this foam seem very small. I cleaned it up with some ISO-alcohol and some of the LEDs started working but some of the key pads quit working. I cleaned it a second time and the same results. Some other buttons are working but some still not. The LED problem is solely the problem of the conductive foam but the keys could also be the conductive pads on the rubber keys. I've measured the resistance on most of the pads and they are about 50 ohms except for some that are 200 ohms and greater (up to about 480 ohms). I'm not sure what the max resistance can be and still make the key function. My solution first is to just solder the two boards with a connection harness to eliminate the conductive foam but I'm not sure how to fix the rubber key problem. I have some conductive paint but the resistance is still high, around 150 ohms. Does anyone have any success repairing this kind of problem?
Gary
