Microwaves typically last about 7 to 9 years. The microwave FAQ lists repairs from $140 to $600, so compare the diagnosed quote with half the price of a comparable replacement to apply the 50% rule. A repair near $600 may not make sense for a basic countertop microwave near the end of its typical life.
A turntable coupler or motor can be worth repairing when the microwave still heats food and the problem is limited to rotation. A door interlock switch is a focused repair when the unit will not start because it no longer detects a closed door. A touchpad or internal fuse can also be reasonable when the fault is isolated and parts are available.
A magnetron or inverter board near the $600 high end is a reason to compare replacement for a basic countertop model. A microwave that trips a breaker, shows arcing, or has damaged door latches needs safety evaluation before further use. For an over-range or built-in microwave, replacement adds installation and cabinet-fit work, so repair can remain worthwhile.
Summer storms can cause power interruptions and surges that damage a microwave's control board or internal fuse. After a surge, repeated breaker trips or a dead display should be diagnosed before the unit is used again, since the visible symptom may not identify the failed part. A suitable surge protector can help protect electronics, but it does not replace inspection of a damaged appliance.
Still not sure? Read our repair or replace guide, or call us for an honest assessment. We will tell you when replacement makes more sense.