genie 34/19 platform control

[k9yli]

I am working on a 34/19. It has a dead platform control. The only thing it will do is , when you switch
the switch to platform, the platform lowers. At times I can use the platform control to raise the jib, but it immediately retracts when I let up o the raise control. Ground controls work fine.
If I plug the platform control into the ground control box to eliminate the boom wireing, i get a constant alarm after about 5 seconds.
Serial is T3401-11.. It has the plastic overlay type of switch with 12 push button locations.
In an attempt to isolate the 'jib down' button which i suspect I bent pin 4 at the ribbon connector out so it should make both up and down jib fail.
But.... Now the entire panel works including jib up and down.
I suspect the sorely beat up bubble switch panel but I can not find the part number for it, although I have read in other postings about someone who had replaced the panel and one on how to do it and clean off the sticky surface to apply the new pad.

The oddity is why does the jib up/down work with the pin 4 'open'?
The platform control is some type of binary combiner of the 12 push buttons into just
4 wire, ground ,+24, data + and data -.......

I went thru all 7 pages of posts. No clear picture or description in the online parts catalog.

 

[VoodooMojo]

Typically to test the control placard for shorted membrane switch at platform or ground controls, just unplug the blue placard plug from the circuit board at suspected control box and cycle on the e-stop switch with the blue plug disconnected....after the watchdog delay (1 to 3 seconds) plug in the blue plug. If functions work then it is indeed the control placard that it at fault.