The short answer
On Forno a machine that will not start is most often no power reaching the machine. Ranked that way because a built-in microwave is held square by its trim kit, so the install is part of the appliance here rather than something that happened once.
What you observe
- Some keys work and others do nothing — A keypad membrane failure, which is a technician job rather than an owner one.
- The display is completely dark — A power problem rather than an appliance problem. Check the breaker and the outlet.
- NEAR MISS: it starts and runs but the food stays cold — That is a heating fault rather than a starting one, and it has its own page.
Causes, most likely first on Forno
- There is no power at the machine — First on a fitted machine, which is only ever as good as its installation. A tripped breaker, an outlet switched off behind a built-in machine, or a plug that has worked loose. A completely dark display is a power problem rather than an appliance problem.
- The programme was never fully entered — Second: on a fitted machine this is the next thing genuinely yours to check. Many machines need a time or a programme entered before start does anything, and a cancel pressed mid-entry leaves the display lit and the machine waiting. It reads exactly like a fault and is not one.
- A child lock or a demonstration mode is set — Third. Both survive a power cut, and both look exactly like a refusal to run.
- The keypad, an interlock switch or the control board has failed — Last, and it is the reason the order above matters. Power is confirmed, no lock is set, the programme is entered and the door latches, and nothing happens.
Check in this order, and why
- Look at the display: dark is power, lit is not — One glance splits the whole list in two, which is why it comes early.
- Enter a short time on a standard programme, then press start — It costs nothing and it resolves a genuine share of these outright.
- Read the display for a lock symbol before pressing anything else — Free to rule out, and it explains a machine that beeps and does nothing.
What an owner can safely check
- Check the breaker and the outlet, and reseat the plug if you can reach it — A breaker that trips again straight away is a fault.
Tools: torchAbout 15 min
- Press cancel, enter a short time on full power, and press start — A machine that runs this way was never faulty.
About 5 min
- Clear any child lock and cancel any delayed or demonstration mode, then retry — Holding the stop or cancel key for a few seconds is the usual clear.
About 5 min
- STOP HERE if the next step needs a meter on live terminals — That is where an owner check ends and a service call begins.
Before you open anything
Safety
Never open the outer casing of a microwave: the high-voltage capacitor can hold a lethal charge long after it is unplugged. Never tape, pack or bypass a door interlock to make a machine start. Switch the breaker off before reaching behind a built-in machine, and never reset a breaker a second time once it has tripped twice on the same appliance.
When to call a technician
Call, or replace the machine, when power is confirmed, no lock is set, a programme is entered, the door latches and it still does nothing, because that puts the fault in an interlock switch, the keypad or the control. Call immediately, with the breaker off, if it trips the breaker when power is restored or if anything smells hot.
Nearest pages of this class
What this page does not cover
This page covers the brand and the microwave class, not one family or model line. Where a family-specific or model-specific page exists for your unit, that page is the more specific answer and it takes precedence over this one. Not here: part numbers, wiring colours and component locations, which differ by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
