Oven display and controls are completely dead; no lights or response when power is applied.

Safety first: Verify the wall breaker is off before opening the rear panel. Only work on live circuits if you are qualified.

• Check external supply: Confirm the kitchen breaker or fuse for the oven circuit is not tripped and that there is voltage at the wall connection.
• Inspect terminal block: Remove the rear cover and check the terminal block for loose or burnt connections. Tighten and repair as needed.
• Internal fuse: Some Tristar ovens have an internal fuse on the control PCB. With power off, locate and test this fuse. Replace with the same rating if blown, but investigate why it blew.
• Control board: If supply and fuse are good but the oven remains dead, the main control PCB power supply is likely faulty and the board must be replaced.

After repair, verify all functions and monitor for any unusual behavior.