What you are looking at
A microwave that will not start is nearly always either not being fed or not satisfying its door interlocks, and the interlocks are deliberately unforgiving. On a Criterion no power at the outlet comes first, because these units are frequently owner-installed in a closet, a garage or a basement corner, so what feeds the machine is as suspect as the machine. Outlet, breaker, door closure and lock settings are owner checks; the interlock switches and the internal fuse are not.
What you observe
- It went dead immediately after a door slam or an arc inside — A blown internal fuse, which is a symptom of something else.
- Completely dead: no display, no light — A supply fault or a blown internal fuse.
- The display works but start does nothing — Usually a door interlock or a control lock.
- NEAR MISS — It stops part way through a programme — Check ventilation and overheating before treating it as a start fault.
Why it happens, in order
- No power at the outlet — Ranked first here: these units are frequently owner-installed in a closet, a garage or a basement corner, so what feeds the machine is as suspect as the machine. A microwave is often on a kitchen circuit shared with everything else, so an unrelated trip takes it out without any hint on the oven.
- A door that is not closing its interlocks — Ranked second: Several switches must all be made; a dropped door, a bent latch or debris in the latch recess leaves one open and the oven does nothing.
- A membrane keypad that has failed — Ranked third: Where some buttons work and others never do, the fault is the keypad layer rather than the electronics behind it. It sits here rather than higher because the drivetrain is simple, which makes it durable — it is a real cause but rarely the first one.
- A blown internal fuse after an arc or a door slam — Ranked fourth, and last: A microwave has a fuse that protects the high-voltage side; it blows because something else went wrong, so replacing it alone is rarely the end of the story. The drivetrain is simple, which makes it durable — it is a real cause but rarely the first one.
What to check first, second, third
- Test the outlet with another appliance and cycle the breaker fully — A dead outlet ends the diagnosis before the oven is involved. Start here: on this platform it is both the most likely finding and the quickest to confirm.
- Close the door slowly and listen for the switches clicking in sequence — One or two clicks where there should be more, or an oven that runs only under hand pressure, identifies the fault.
- Map which buttons respond — A pattern — a row or a corner — is characteristic of a keypad failure.
The checks you can do yourself
- Prove the outlet, cycle the breaker fully off and on, and reset any protective device — Kitchens often have a device covering several sockets; reset it properly rather than nudging it.
About 10 min
- Clean the latch recess and the door hooks and check the door closes flush — Never tape, wedge or force a door — the interlocks are what stop the oven generating when it is open.
Tools: clothAbout 15 min
- Stop here if the next move needs a meter on live terminals — That is where an owner check ends and a service call begins.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Nothing here asks you to take the outer cabinet off, and a door interlock is never taped or defeated.
The line between DIY and a callout
Call once the outlet is proven, the breaker cycled, the door latching firmly and no lock is set — and call rather than investigate if the oven went dead after a bang, an arc or a burning smell.
The same machine, other symptoms
What is deliberately not here
This is the family-agnostic page for Criterion microwaves. Nothing more specific exists to send you to at the moment; a model-level page, once written, is linked here and is the better answer. Deliberately not here: wiring colours, resistance values, torque figures and part numbers, which differ between families.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
