GE Microwave Model PVM1790SR1SS Rotary Control

[Robear]

Greetings,

I have a GE microwave model PVM1790SR1SS.   It has a control pad with a rotary control that is also a button that you turn to select a setting and then press to enter.   The button 'press' has become less and less responsive lately.   I know I can replace the entire control panel circuit board, but since the problem seems to be just the button, I would rather just replace that.   I have the solder skills and equipment to accomplish this.   I am unable to find the part number for this rotary control/button however.   Can anyone assist?   Thank you.

[ECtoFix]

22 hours ago, Robear said:

I know I can replace the entire control panel circuit board, but since the problem seems to be just the button, I would rather just replace that.   I have the solder skills and equipment to accomplish this.   I am unable to find the part number for this rotary control/button however.   Can anyone assist?

Not really.  That rotating component (an encoder is what I think it's called) was unfortunately made as an integral part of the board - which is and always has been a dumb idea. 

GE will only sell you the entire board.  Very few (if ANY) technicians will pursue a repair like you're suggesting because it add labor to find a source for those board components and requires tools that many don't carry in their service vehicles (they're simply not needed as a norm).

While I personally have some decent soldering skills, the boards nowadays are multi-layered and wrought with what's called "surface mount technology" (SMT) - vice through-hole technology.  SMT is more prevalent nowadays due to the cheaper cost of manufacturing a board.  However, such boards are nearly impossible to to repair due to multi-layering of boards and the minute solder joints used to attach components.

You should just go ahead and replace the board.

[Vance R]

+1 For what @ECtoFix stated.

[MTech2]

Robear, I know it is too late for you, but maybe this will help others:

So I just this morning had the same problem.

I cleaned the board & ribbon cable using isopropyl; grease seemed to permeate the enclosure.

I checked the switch portion of the rotary encoder, using a DVM, and it actually was working fine!

I put it back together and now the pushbutton is working!

 

Having said that, the rotary encoder on this microwave doesn't appear to be anything special. If you can match shaft length and pinout configuration it should be an easy swap, I had some encoders laying around that looked like it would fit the bill). The hardest part will be getting it unsoldered from the board, so you'll need to use some de-soldering techniques & tools, like a copper ribbon or a vacuum. I've done this kind of job many times and it is pretty straight forward (no layered boards or SMDs involved). It should take 30 minutes or less. (I am a pretty experienced in soldering so YMMV)