Microwave Oven Problems and Repair
Most microwave problems have a simple cause. Here are the safe checks you can do yourself, and the faults that need a trained repairer.
Updated 11 November 2026
Safety first
Never open the outer cover of a microwave yourself. The high-voltage capacitor inside can hold a dangerous charge even after you unplug it. Do only the outside checks below, and leave inside repairs to a trained technician.
Microwave not turning on
- Check the plug, the wall socket (try a phone charger) and the main switch.
- Check if child lock is on (a lock sign on the display). Hold Stop for about 3 seconds to unlock on most models.
- Make sure the door closes fully; a door switch will not let the oven run if the latch is not caught.
- If the display is dead, the internal fuse may have blown. This needs a repairer.
This is the most searched problem for Haier and Kenwood ovens.
Microwave not heating
If the light and turntable work but food stays cold, the fault is usually the magnetron, high-voltage diode or capacitor. These need a repairer. Before calling one, check that you did not set a low power level or Defrost by mistake, and that the voltage is not very low.
Microwave sparking
- Remove any metal, foil or plates with gold rims.
- Clean food splashes off the mica sheet on the side wall; burnt food there can spark.
- If the mica sheet is burnt or broken, replace it.
- If sparking continues on an empty clean oven, stop using it and get it checked.
Turntable not rotating or making noise
Check that the glass plate sits on the roller ring and the centre coupler. Clean the roller ring. If it still does not turn, the turntable motor may need replacing. A loud hum or buzz with no heating means a repairer should check the magnetron.
Light not working and outside getting hot
A dead inside light is usually just the bulb. The outside of the oven gets warm with use, especially at the top and back, which is normal. Leave space around it for air.
Repair or replace?
If the magnetron fails on an old, cheap 20 litre oven, a new oven may be the better buy. See Microwave Oven Under 25,000 in Pakistan. For newer ovens, first check your brand warranty card. New ovens from us come with a 7-day checking warranty.
Microwave runs and the light is on, but it is not heating
This is the most common microwave fault. The lamp, fan and turntable work, but the food stays cold. The usual causes, from most to least likely, are:
- A blown high-voltage fuse
- A failed high-voltage diode
- A weak or failed capacitor
- A worn-out magnetron
- A faulty door switch that lets the lamp run but blocks heating
All of these parts sit in the high-voltage circuit. The capacitor can hold a dangerous charge even when the oven is unplugged, so testing the transformer, diode or magnetron is a job for a trained technician, not a home repair.
Fuse keeps blowing
If the main fuse blows again soon after it is replaced, something else is causing it: most often a failed door switch, a shorted diode or capacitor, or a magnetron fault. Fitting a bigger fuse is dangerous and can damage the wiring. Have the oven checked, and tell the technician exactly when the fuse goes (when you open the door, or when you press Start).
Buttons, touchpad or display not working
- Unplug the oven for 5 minutes to reset the control board, then try again.
- Check that Child Lock is not on. On many ovens you hold Stop or Cancel for 3 seconds to unlock it.
- If only some keys fail, the membrane touchpad may be worn or damp. Grease and steam near the panel are common causes.
- A blank display with no lamp often means a blown fuse or a power problem.
Touchpads and control boards are model-specific spare parts, so note the full model code from the label inside the door.
Microwave error codes
Error codes differ between brands. Codes such as E1, E3 or E5 on many ovens point to a sensor, overheating or door problem, and PF usually means the power failed. Unplug the oven for a few minutes, check the door closes firmly, and try again. If the code returns, look it up in your manual or ask the brand service centre. Do not keep restarting an oven that shows an overheating code.
How long does a microwave oven last?
A well-kept home microwave usually lasts around 7 to 10 years, and many last longer. Things that shorten its life are running it empty, letting grease and food build up around the door, frequent voltage drops, and blocking the side or back vents. Keep at least a few centimetres of space around the oven, use a stabiliser if your area has bad voltage swings, and clean splashes before they burn on.
Door latch, plate and diode problems
- Door latch: if the oven will not start or stops when you touch the door, the latch hooks or door switches are worn. These are cheap parts, but fitting them needs the cover off, so call a technician.
- Glass plate: a cracked turntable plate must be replaced, not used. Buy one of the same diameter, because sizes differ by model.
- High-voltage diode: a failed diode often causes a loud hum and no heating. It sits next to the capacitor, which can hold a deadly charge even when unplugged, so this is a job for a trained technician only.
