Screen only shows "Turn Dial" and no functions work after replacing Control Board

Microwave Repair
1

Brand:
Model Number: PSB1001NSS01
Main Symptom: No buttons work and it only shows “Turn Dial”
What happens & when: The screen was blinking erratic and would blank out. The only function I could use was the 30 second quick reheat. I replaced the digitron about 6 mos ago and the screen was brighter and some of the issues cleared up but not all. It still blinked and while cooking the screen wouldn’t show anything. When it was done cooking the screen would show again. Today I replaced the microwave control board and now it only shows “Turn Dial” and no other buttons work. I put the old control board back in and now it shows the same thing “Turn Dial”

Error Code (if any): None
Parts or tests already tried: Digitron & Control Board, See above
Photos / video link: NA

2

Hi Cisaacs, thank you for your post.

Since there are three different control boards in this model that can influence operation in this way, could you confirm which specific control board was replaced? If possible, please provide the part number of the control that was installed.

That information will help narrow down where testing may need to begin.

3

Hi William,

Good morning and thanks for getting back to me. The part number that I replaced was (WB27X10858). After letting the microwave sit for a while it let me set the time etc. Now it is working again with button functions but it’s still blinking erratically and the screen goes blank while cooking. Thanks!
v/r

Clif

4

If the microwave can be set on a countertop, the top and side panels can be removed to allow access for voltage testing. This will help narrow down the cause of the failure. For this test, needle lead probes will be needed to safely reach the terminals.

After the panels are removed, locate the low-voltage transformer connections going to the power control board at connector CN7.

With the power cord plugged in, use a multimeter set to Volts DC and take the following measurements:

  • Yellow wire to black wire — should read about 12 Volts DC

  • White wire to black wire — should read about 19 Volts DC

  • Red wire to brown wire — should read about 7 Volts DC

Do the voltage readings differ from these values when you perform the test? Let us know what readings you find and we can help determine the next step.