Tip & How-To about Microwave Ovens

How to discharge a microwave oven's capacitor:

Discharging a high voltage capacitor

Discharging your microwave's capacitor is absolutely essential in preventing injury to your microwave, your tools, and yourself. A capacitor stores large amounts of electricity even when your microwave is unplugged, and it must be discharged before beginning any repair.

A capacitor is discharged by creating a short circuit between each of the two capacitor terminals, and between each terminal and the chassis. The chassis is the metal mounting (bare metal surface) of the capacitor. Read these directions thoroughly before you proceed.

With your microwave unit unplugged, touch the blade of a well insulated screwdriver to one terminal. Gently slide the screwdriver forward until it reaches the other terminal, holding it there for a few seconds. Be aware that this often results in a loud and startling 'POP'.

Repeat this procedure in order to create a short circuit between each capacitor terminal and the chassis (bare metal mounting plate surface). This same method can be applied to a capacitor having three, and not two, terminals.

I hope this helps.

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2 Answers

Microwave pvm1870sm3ss not heating and have no wiring diagram


You don't need a wiring diagram if you have basic knowledge of how a microwave works. The gadget responsible for heating is the magnetron just google to have an overview. How ever it must be powered by high voltage from a transformer. If the microwave indicates it is on yet not powering, just open the cover only don't touch capacitors inside without discharging first to discharge just short the capacitor with an insulated screw driver check for continuity with digital multi meter on the primary of the high voltage transformer if ok change your magnetron and you will have your microwave back and functioning just make sure not to plague on the A.C Mains while you are working on it.

Mar 23, 2016 | GE Microwave Ovens

1 Answer

everything functions but it will not heat food


Before you remove the microwave casing, you need to read up on how to discharge a high voltage capacitor, i'd explainb it here but i feel much safer if you were to look it up and fully understand it before attempting any repairs as the high voltage capacitor can cause fatal injury and/or death.

Ok, after reading up about how to discharge a high voltage capacitor, this is what you need to check out.

Step 1, remove the microwave casing and discharge the high voltage capacitor to prevent injury or death.

Step 2, Look for the fuse which you may find in a small plastic case with wires coming from each end, one end leading to the high voltage capacitor and the other end leading to the transformer and the magnatron assembly, the magnatron, or maggy, has a cube-ish shape and contains magnets which are visable through the grill. You will be able to see with the naked eye if this fuse is faulty as it will look like a blown fuse, if so, replace the fuse.

Step 3, At this point if you have a spare fuse you can VERY CAREFULLY plug the unit in and VERY CAREFULLY test it to see if it heats, if it does heat then VERY CAREFULLY unplug the unit, discharge the capacitor, and replace the case. If it still isnt heating you will need to replace the magnatron assembly, contact your authorised repair agent or the manufacturer or the microwave for directions to spare parts. Be very careful with new magnatron assemblys because if you drop it, you will damage or fracture the magnts within and render it useless.
I hope this helps. Good luck.

Apr 12, 2010 | GE Spacemaker JVM1640SJ Microwave Oven

1 Answer

runs like normal but won't heat anything. Microwave randomly turned on by itself. It ran for a while without anyone noticing. Now it will turn on but it won't heat heat anything up.


Before you remove the microwave casing, you need to read up on how to discharge a high voltage capacitor, i'd explainb it here but i feel much safer if you were to look it up and fully understand it before attempting any repairs as the high voltage capacitor can cause fatal injury and/or death.

Ok, after reading up about how to discharge a high voltage capacitor, this is what you need to check out.

Step 1, remove the microwave casing and discharge the high voltage capacitor to prevent injury or death.

Step 2, Look for the fuse which you may find in a small plastic case with wires coming from each end, one end leading to the high voltage capacitor and the other end leading to the transformer and the magnatron assembly, the magnatron, or maggy, has a cube-ish shape and contains magnets which are visable through the grill. You will be able to see with the naked eye if this fuse is faulty as it will look like a blown fuse, if so, replace the fuse.

Step 3, At this point if you have a spare fuse you can VERY CAREFULLY plug the unit in and VERY CAREFULLY test it to see if it heats, if it does heat then VERY CAREFULLY unplug the unit, discharge the capacitor, and replace the case. If it still isnt heating you will need to replace the magnatron assembly, contact your authorised repair agent or the manufacturer or the microwave for directions to spare parts. Be very careful with new magnatron assemblys because if you drop it, you will damage or fracture the magnts within and render it useless.
I hope this helps. Good luck

Apr 06, 2010 | Magic Chef Microwave Ovens

1 Answer

Light is burnt out. How do I replace the bulb for an EM-S260


Befor you do anything you need to read up on how to discharge a high voltage capacitor so that you avoid all sort of injury as well as death. Once you have read up on how to discharge the high voltage capacitor, you simply remove thecasing of the microwave, discharge the high voltage capacitor, once that is done, you are safe to locate and replace the bulb, To obtain a bulb contact your closest Sanyo authorised repair agent, they should either have one in stock or they will be able to order one for you.. Good Luck.

Dec 02, 2009 | Sanyo Microwave Ovens

1 Answer

jvm1533wd spacemaker wont heat up and has a loud humming noise


I have found that in nearly all cases, it can either be the high voltage fuse or the magnatron assy. The high voltage fuse can be found normally enclosed running from the high voltage capacitor to the transformer. Always make sure you read up on discharging high voltage capcitor , for it can store a dangerous amount of voltage and if not discharged can cause serious injury or death. Good luck.

Sep 26, 2009 | Microwave Ovens

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