The short answer
A Black+Decker microwave showing this usually tells you one thing: a countertop oven that refuses to start is usually reporting a dead socket or a worn door latch. Both checks are free and take a minute. Past them the case stays closed and the question becomes repair against replace.
What you actually see
- Nothing at all when the door is closed and start is pressed — No display, no light and no fan is a supply picture.
- The display is lit but pressing start does nothing — A live display with a dead start is a door or a control question.
- The display shows a time that will not count down — A frozen countdown is a control state rather than a mechanical fault.
Causes, ranked for this microwave
- No power at the outlet — The usual answer. it is first because it is free to test and because a switched socket or a tripped protection device explains a large share of these calls. Rule it in or out properly here; a maybe at this position costs an hour further down.
- Door not latching properly — The runner-up. it produces a total refusal to start on a machine that is otherwise healthy, which makes it the highest-value free check on this page. Getting a definite answer here is worth more than a quick look at the three below it.
- A mode, lock or timer left set — Third. child locks and demo modes are entered by holding a button and produce a machine that beeps and refuses, which reads exactly like a failure. If this is the answer, the rest of the list stops mattering entirely.
What to check, in order
- First — the outlet — Check the breaker and any protection device on that run. A standard household branch circuit is 15 or 20 amps and a microwave is a heavy user of it.
- Second — the door latch and striker — Close the door and listen for a clean double click, then press it firmly and try again. A start under pressure convicts the latch.
Checks an owner can do safely
- Step 1. Power-cycle the oven — Unplug it for several minutes until the display is fully dark, then restore power and try again.
Tools: noneAbout 10 min
- Step 2. Test every button — Press each button in turn and note which respond. A dead start button with a live number pad is a keypad fault.
Tools: noneAbout 5 min
- Step 3. Test the outlet with something else — Plug a lamp or a charger into the same socket. A dead socket means the oven is not the fault.
Tools: lamp or phone chargerAbout 5 min
Before you open anything
Safety
Unplug it, and treat the inside as off limits. The high-voltage section of a microwave remains dangerous with the power disconnected. A damaged door, a bent latch or a failed switch is a reason to stop using the oven, never a reason to work around it.
When this becomes a service call
Stop and call when the next thing to do meets any of these. The case stays closed whatever the fault. A microwave holds a dangerous charge after it is unplugged, and no owner check goes behind the panel.
Sources
General guidance- The Control of Hazardous Energy (Lockout/Tagout) — OSHA 1910.147 and manufacturer service manuals, fetched
- Article 210 — Branch Circuits — NFPA 70 (National Electrical Code), fetched
Nearest pages
What this page does not cover
Treat what follows as the class-level answer for a Black+Decker microwave. It will not tell you which board your unit has, which part number fits it, or what a particular code means on a particular family, because those differ within the range. The family and model pages beneath this one carry that, and they are linked under Related pages.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
