Troubleshooting QUV controller board/keypad interface

[ppkjref]

My issue is the bottom row of buttons on the keypad shown below not working. So far I have tried:

Installing a new keypad
Disconnecting all controller board inputs except for the power supply and keypad ribbon cable
Checked the keypad interface ribbon cable for continuity

These steps lead me back to the 26 pin header (which looks fine) on the main controller board but I am unsure of where to go from here. This is for a Q-lab accelerated weathering tester. Any suggestions?

 

[davenn]

My issue is the bottom row of buttons on the keypad shown below not working. So far I have tried:

so that means the fault is in the common line for that row. You can see that the common line is the trace on its own on the plastic ribbon cable
you need to ensure continuity right through to the main board in photo #3 .... you will have to work that out then show us which line on the PCB it is

Then tracing from there can begin


cheers
Dave

 

[73's de Edd]

Sir ppkjref . . . . .

KEYPAD . . .contact breakdown

http://i.imgur.com/oNKfUMH.jpg


Needless to say, if you are loosing the WHOLE bottom string of contacts, you are loosing A connectivity somewhere down the interconnecting wiring line.


73's de Edd

 

[davenn]

Needless to say, if you are loosing the WHOLE bottom string of contacts, you are loosing A connectivity somewhere down the interconnecting wiring line.

I had already established that for him and had got him moving further along the system