911494 Kenmore Microwave Oven Combo - Overview

Turned out the issue was easily solved by replacing a single, inexpensive fuse.

First off, UNPLUG THE MICROWAVE.

The fuse is located under the plastic grill at the top of the microwave. It's held on by two screws. Once you've removed the screws and taken off the plastic grill, you go to the right side of the mic ... Read more rowave and remove another screw that holds a small metal grill in place. Removing the small metal grill is probably the toughest part of this repair. You kind of have to rock it back and forth a bit to get it to release. Once that's off, you can get to the fuse. I removed the burnt out one with a pair of needle nose pliers. I also put a small piece of cardboard under the fuse when I did this so I didn't accidentally drop it into the innards of the microwave. I did the same thing when I replaced the new fuse. I then plugged the appliance back in and made sure it worked. Once that was confirmed, I replaced both grills.

This repair is EASY if you know how to use an ohm meter. If not, seek help for this step.

SYMPTOM:
The oven (JKP27WOP3WG or JKP27WP3WG and many ovens like it ) was not getting hot enough. Verifying the cooking temperature with an typical oven thermometer, I was able to determine that the oven was cooking temperature was ... Read more about 150 degrees to low.

FAILURE POINTS:
There are two logical failure points (1) The oven sensor ( WB21X5301 about $75), or the (2) the controller board (PS238233 about $252). In my case it was the controller board. When replaced the oven worked beautifully.

REPAIR:
As with any repair, you MUST DISCONNECT POWER TO THE UNIT BEFORE SERVICING!!!

Pull oven from the wall:
- Disconnect power by flipping the circuit breaker to the OFF position.
- Remove the top flange / cowling from the top of the oven (it just pulls off)
- Remove two screws under the top flange / cowling
- The whole unit easily slides out, but it is highly recommended that you use two people to place the oven on the floor.

As a diagnostic between these two parts, if the oven sensors measure approximately 1.1K ohms of resistance at room temperature, then it is probably not the sensor. The oven sensor wires are connected to two white wires that run up to the controller board. You need to disconnect the oven sensor to make the measurement. You may either completely remove the oven sensor by cutting the wire (be sure to allow yourself enough slack so that they may be safely reconnected) where it connects to the white wires, OR, (preferred method) if leaving the oven sensor partially installed,
- Remove the top sheet metal cover (10 screws)
- Remove the service connect cover (2 screws - this is where the main Power cord comes into the unit)
- Disconnect the white wires from the controller board (this connector which also includes other circuits is on the left side when looking at the controller board).
- Remove two screws from oven sensor but just let in dangle down so that you can put the sensor in the ice water / boiling water.

Measure the resistance under the following conditions. Your ohm meter should read APPROXIMATELY...
- 1.02K ohms in ice water
- 1.09K ohms at room temperature
- 1.36K ohms in boiling water.
If you get approximately these readings, then it is NOT the oven sensor. If that checks out then re-install the sensor AND the connector.

If it is NOT the sensor, replace the controller board.
- Take a moment to write down the color of the wire to the LETTERING (N, L, G, C / COM,,,) on the controller board. The connectors are in different locations on the new controller board so the wire color to the letter designation is significant.
- Carefully remove the wires one at a time
- VERY carefully remove the keypad ribbon cable from the right side of the controller board.
-- The ribbon cable will disconnect by releasing some little pressure clips on the side of the connector.
- Remove the controller board (4 screws)
- Install new controller board (4 screws)
- VERY carefully connect the keypad ribbon cable on the right side.
-- Make sure that the connector is in the OPEN position first, then,
-- Slide in the cable ensuring that all parts of the ribbon made it into the connector, then
-- Press down on the connector locking tabs.
- Reconnect each wire to the correctly lettering on the board.
-- Again, the connectors MAY BE in a different order on the replacement controller board. Match color to letter.
- Reconnect the (5 wire?) connector that includes the white oven sensor wires.
- Make sure everything looks normal, (i.e. no wires are pinched, remove tools from top of oven area, etc.)
- Re-install top cover.
- Re-install service connect cover.

You can test the unit while it is out of the cabinet,
- Make SURE that all sheet metal covers are in place.
- Flip power breaker to "On".
- Test that oven gets to the desired temp.

Removed six 1/4" hex nuts on rear of oven. Then through front/inside removed a single 1/4" hex nut to actually remove sensor. Unplug sensor connector, remove. Reversed steps, push oven back in place and plugged in. Tested oven function.