Display characters blink at times

General
1

Please make sure to click on General above and select the correct appliance type first.

Brand: GE
Model Number: PSB1001NSS01
Main Symptom: Display characters blink at times.
What happens & when: The display characters intermittently blink at times. Unplugging the unit for 15 seconds and plugging back in resolves the problem for a day or two. The unit is wall mounted over an oven.

Error Code (if any):None
Parts or tests already tried: None yet.
Photos / video link:

2

Thank you for your question.

Based on the issues you’re describing, I would suspect that the control board may have an intermittent fault. When this problem occurs, is anything else happening at the same time, such as the microwave running while the oven is in use, or another appliance operating on the same electrical circuit?

I have also enclosed a copy of the GE service manual for your microwave. It contains troubleshooting and diagnostic information that may be helpful in identifying the cause of the issue.

Please let us know what you find, and we’ll be happy to assist further.

PSB1000NBB01 31-41019-Mini-Manual-5395.pdf (2.0 MB)

3

Are you referring to the board WB27X10861 or WB27X10858?

4
5

Replaced digitron board, new board won’t power up microwave, old board does power up microwave.

6

Since the old digitron powers the microwave up and the new WB27X10856 does not, I would not suspect the microwave’s main power supply first. GE confirms WB27X10856 is the correct digitron for PSB1001NSS01.

I’d check the installation before condemning the new board:

  1. Disconnect power and reinstall the new digitron. Reseat every ribbon cable and plug. Pay particular attention to ribbon cables being fully inserted, straight, and with the contacts facing the same direction they did on the original board.
  2. Inspect the new board connectors for a bent/recessed pin or damaged ribbon socket.
  3. Compare the old and new boards side-by-side. Verify WB27X10856 is printed on the replacement and that all connector locations/components match.
  4. Reinstall the old digitron again. If the microwave immediately powers up normally, that is a very strong A/B test: the wiring, transformer/power supply, and associated controls are at least capable of operating the unit with the original board.
  5. If desired, repeat the swap once more: old works → new dead → old works. At that point I would consider the new WB27X10856 defective rather than start replacing additional boards.

This model does have several separate controls—the WB27X10856 digitron, WB27X10858 control board, WB27X10861 power board, and WB27X10859/WB27X32849 relay board—so normally a dead display can involve more than the digitron. But because simply putting the old digitron back in restores operation, the replacement digitron or its connection is the leading suspect.

One caution: I wouldn’t recommend live-voltage probing around this Advantium unless you’re experienced with microwave servicing. Even unplugged, the high-voltage section can retain a dangerous charge.

7

I apologize as I failed to indicate that I tried a new replacement digitron board. I also did an ohm/resistance test on every pin on the connector to assure a good connection. Microwave display blank and unit wouldn’t run. Again I removed the new board, installed the old board and the unit runs. Display was blinking, I left in plugged in over night, now the display acts normal, with the old board it was acting intermittent as it is now.

8

I would recommend returning that new board and getting a replacement

9

I have called APP the other day and they sent a replacement digitron board WB27X10856, same part number, and that replacement board is doing the same thing when installed as the first new board. The board part number matches the original, the IC chips are physically larger in size on the original board FYI.

10

can u send me pictures of both sides of both boards

11

IMG_6824
IMG_6824640×480 127 KB

IMG_6825
IMG_6825640×480 122 KB

12

PSB1000NBB01 31-41019-Mini-Manual-5395.pdf (2.0 MB)

The only documentation I could find on your model is attached.

13

can u send me order number we’re going to do some checking on our end

14

The order number is 17279902.

The model number is PSB1001NSS01 The serial number is DZ300150K

15

We are investigating if it’s a bad batch of boards due to the dissimilar arrangement of processors and a few other differences we noted. Someone should be reaching out to you in the next day or so

16

Thanks for do that and looking forward to what you find.

17

we shipped a different board from a different vendor let us know if the board looks different from yours.

18

Thanks, I’ll do that. I’ll watch my email for the shipping info.

19

The replacement board matches the other two sent by APP. I have attached a photo of the board that came today and the board that was in the unit.
Do you want me to install the board from today and try it?

IMG_6831
IMG_6831480×640 116 KB

IMG_6832
IMG_6832480×640 106 KB

20

I’ve talked to 3 other techs who are more familiar with these digitron equipped GE Microwaves and they all agree on the possibility of a HV transformer issue causing intermittent power fluctuations. The redesigned board could possibly sense these fluctuations and can’t operate. At this point we’re really scratching our heads. I would seriously recommend having a Tech actually look at and test the unit