Tristar
Control Timing / Relay Logic Fault
Microwave fan and light run but the timer does not count down; cooking never completes.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Defective control PCB timer circuit, Stuck relay feedback, Corrupted control firmware, Keypad START input not properly registered
How to Fix / Troubleshooting
Safety: Unplug the microwave before accessing the control panel.
Steps to address non-counting timer:
- 1. Verify correct operation: Ensure you are pressing START after entering time or selecting a program. Some models require explicit confirmation.
- 2. Power reset: Unplug for 5–10 minutes and test again.
- 3. Check keypad: Confirm that the START button is responsive. If not, the keypad may be faulty.
- 4. Replace control PCB: If the keypad is good but the timer still does not count, the control board logic is likely defective and must be replaced.
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Repair Difficulty
Medium
3/5
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