Brand: KitchenAid
Category: Microwave Oven
Document Type: Parts/Service
Language: EN
Parts/Service for KHMS105E
Uploaded: Nov. 21, 2025, 6:07 p.m.
Manual Publish Date: 1997-03-01
Warranty Information
KitchenAid assumes no responsibility for repairs made by anyone other than authorized technicians.
The microwave oven is powered by the 120-volt line. When the door is closed and a cooking function is programmed through the control panel's keypad, relay contacts on the control board close, and complete a circuit from the L1 side to the neutral side of the line. The control board uses six relays to operate the various functions of the microwave oven. The relays are controlled by the microcomputer on the control board, and perform the functions shown below. Relay 4 controls the speed of the blower motor through the control panel. The base thermal fuse will also turn the blower motor on to its low speed if the temperature reaches 133°F.
Troubleshooting and error codes
| PROBLEM | POSSIBLE CAUSE | TEST PROCEDURE OR CORRECTION |
|---|---|---|
| Blower motor will not operate. | 1. Blower motor. 2. Control board. 3. Open or loose wiring in circuit to blower motor. |
1. Check blower motor. 2. Check control board. 3. Use ohmmeter to check continuity, and repair wiring. |
| Cooktop lamps do not come on. | 1. Bulb burned out. 2. Control board. 3. Lamp sockets. 4. Open wiring between the above components. |
1. Check bulb. 2. Check control board. 3. Check lamp sockets. 4. Use ohmmeter to check continuity, and repair wiring. |
| Oven heats too fast. | 1. Line voltage is too high (should be between 108- and 132-volts AC). 2. Control board. |
1. Use separate 15- to 20-ampere circuit. 2. Check control board. |
| Oven cooks too slowly. | 1. Line voltage is too low (should be between 108- and 132-volts AC). 2. User error. 3. Magnetron. |
1. Use separate 15- to 20-ampere circuit. 2. Instruct user regarding proper cooking times. 3. Check magnetron. |
| Speaker does not sound at conclusion of cooking sequences, or after elapsed time in Minute Timer. | 1. Open connection or failed speaker. 2. Tones are programmed out. |
1. Check speaker. 2. Program tones back in. |
| Oven cooks on "HIGH” when a lower cook power is selected. | 1. Shorted relay. 2. Control board. |
1. Check the control board. 2. Check control board. |
| Oven runs but will not cook. | 1. Secondary interlock switch. 2. Relay 2 is open. |
1. Check secondary interlock switch. 2. Check control board. |
| Console will not display data, or has incorrect data. | 1. No power at wall plug. 2. Open line fuse. 3. Thermal fuse. 4. Thermal fuse on magnetron. 5. Interlock safety switches. 6. Control board. |
1. Check fuse or breaker box. 2. Replace line fuse. 3. Check thermal fuse. 4. Check magnetron thermal fuse. 5. Check interlock safety switches. Replace, if defective. 6. Check control board. |
| Erratic console display during operation. | 1. Magnetron. | 1. Check magnetron. |
| Display continues to count down when door is open during a "Cook” cycle. | 1. Secondary interlock switch. 2. Control board. |
1. Check secondary interlock switch. Replace, if defective. 2. Check control board. |
| Oven operates without a "Start" command. | 1. Defective control board. | 1. Replace control board. |