F5
Tristar
Relay or Triac Failure on Control Board
Microwave displays F5 and beeps; cooking functions are disabled.
Advertisements
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.
Advertisements
Possible Causes
Stuck relay controlling magnetron or fan, Shorted triac for turntable or fan, Burnt solder joints on control PCB, Surge-damaged control components
How to Fix / Troubleshooting
Safety: Unplug the microwave before accessing the control board.
Steps to address F5:
- 1. Power reset: Unplug for 5–10 minutes and test again. If F5 returns, internal control components are likely damaged.
- 2. Visual inspection: Remove the control panel and inspect the control PCB for burnt areas, cracked solder joints, or damaged relays.
- 3. Replace control PCB: Because relay and triac components are not typically serviced individually on consumer microwaves, replace the entire control PCB with the correct Tristar part.
- 4. Check for underlying causes: If a relay controlling the magnetron failed, a shorted magnetron or high-voltage component may have caused the failure. Have a technician evaluate the high-voltage system if F5 recurs after board replacement.
Advertisements
Repair Difficulty
Hard
4/5
Advertisements