The short answer
A microwave keypad that ignores presses, a display that is blank, or an oven that beeps and refuses is most often locked, interrupted or waiting on its door rather than electronically failed. A supply interruption or a loose plug is the first thing to suspect on a Criterion, 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. Power cycling, lock clearing and door checks are owner work; the keypad, control and anything behind the cabinet are not.
What it looks like from the front
- The display is blank with the oven plugged in — Supply or an internal fuse rather than the control.
- Some buttons work and others never do — A keypad layer fault, and the pattern proves it.
- It beeps and refuses to accept a programme — A lock state, or a door it does not consider shut.
- NEAR MISS — The display dims or blanks after a while — Many ovens dim their displays to save power; that is by design.
The causes and their order
- A supply interruption or a loose plug — Top of the list on this brand: 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 clock that resets and a control that behaves oddly usually share a cause: the oven is losing power briefly and repeatedly.
- A door the oven does not consider closed — Second most likely: Many controls will not accept a programme until the interlocks are made, and the refusal looks exactly like a keypad fault. It sits here rather than higher because the door hardware is light, so it goes out of adjustment before anything electrical does.
- A membrane keypad that has worn through — Third most likely: Steam, grease and years of pressing wear the membrane, and buttons fail in patterns — a row, a column, a corner.
- A blown internal fuse — Fourth and the least likely here: A dead display with a proven outlet usually means the internal fuse has opened, and it opened because something else failed. The drivetrain is simple, which makes it durable — it is a real cause but rarely the first one.
Working order
- Check the plug is fully home and the outlet is not loose — A plug that moves in a worn socket is a supply fault with electrical-safety implications of its own. It leads 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, so proving or clearing it immediately narrows everything below.
- Close the door firmly and listen for the interlock clicks — A control that accepts input once the door is pressed has told you where the fault is.
- Map exactly which buttons respond — A geometric pattern is characteristic and it tells a technician which part to quote.
Owner-side steps
- Unplug for a minute, reseat the plug firmly and power the oven back up — If the clock then keeps time and the keypad responds, the supply was the problem.
About 10 min
- Clean the latch recess and the door hooks, and check the door closes flush — Grease in the latch openings is the most common cause on this appliance.
Tools: cloth, cotton budsAbout 20 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.
Working safely on this machine
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.
When this becomes a service call
Call once the outlet is proven, the plug is firm, no lock is set and the door latches properly — the keypad, the fuse and the control are all behind a cabinet that must not be opened by an owner.
The same machine, other symptoms
How specific this page is
This page covers Criterion microwaves as a class, not one family or model line. There is no per-model page under this one today. Where one appears it is linked from this block and it is the page to trust for a specific cabinet. 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.
