Sanyo EM-710F display dead

If you do not have any experience in the repair of microwave ovens do not engage in their repairs because it is one of the most dangerous household appliances and the consequences can be disastrous. According to your description, low voltage circuit (220V or 110V) works well (light, turntable...). Obviously the problem is in a high voltage (HV) circuit which is made up of the magnetron, HV diode (rectifier), HV capacitor and HV fuse or protect diode. Failure is in any of these components in "HV circuit" or sometimes in interlock switch assembly or PC Board.

First, you must be sure which diode is blowed, reactifier or protect diode.

To check magnetron following this procedure:

Discconect the mains supply.
Check that the capacitor is discharged (by resistor 100 ohm / 10W or more).
Discconect the magnetron.
Measure the resistence between the disconnected terminals (should be app. 0.5 ohm).
Measure the resistance between the supply terminals (both) and earth. The resistance should be infinite.



Dado

see this causes and fix it. GOD BLESS YOU
Power Diode

A diode is an electronic component that readily passes current in one direction only and blocks the flow of current in the opposing direction. If your microwave's diode has become defective, your microwave will not heat and you will hear a buzzing noise. Test the diode to determine if this is the cause of your problem. Replace it if it is defective.

• How to test a microwave diode.
• How to replace a microwave diode.



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High Voltage Capacitor

A capacitor is an electrical device which stores electricity. A defective capacitor may be why your microwave is not heating but you are hearing a buzzing or humming noise. The capacitor will have to be tested to determine if this is the cause of your problem. A defective capacitor will have to be replaced before your microwave will work again. Make sure you discharge the capacitor before you test it, though.

• How to test a microwave capacitor.
• How to replace a microwave capacitor.



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Magnetron

A defective magnetron is the third possible cause of why your microwave is not heating, but you can hear a buzzing noise. Test your microwave's magnetron. Replace it if it is defective.

• How to test a microwave magnetron.
• How to replace a microwave magnetron.

Thermoprotector If the microwave doesn't heat the thermoprotector may have tripped. This is a safety device to prevent the microwave from overheating. It can be tested for continuity to see if it's blown.

Main Control Board If the microwave doesn't heat the main control board may be defective. This is not common. When a microwave doesn't heat the problem is usually within the high voltage circuit; either the high voltage capacitor, diode, transformer or magnetron.
High Voltage Transformer If the microwave does not heat, the high voltage transformer might be burned out. Microwave ovens produce a very high voltage in order to power the magnetron antenna, which emits the energy that cooks the food.

It sounds like the magnetron may have either failed or is not being supplied with the extremely high voltage required to run it.

YOUR SAFETY IS PARAMOUNT

This is a job for a professional but if you are safety clued up, here's instruction.
Make sure the !!!!any capacitors are discharged!!!!! before attempting any sort of repair.
Check the door interlock switches first then the high voltage diode with either an AVO model 8 or moving coil meter on high resistance range for short circuit, (DVM's won't show the fault!), the capacitor can fail and go short circuit, the feed fuse on the primary of the high voltage transformer and then finally, the magnetron is best checked by substitution.
Hope that helps.

It sounds like the magnetron may have either failed or is not being supplied with the extremely high voltage required to run it.

YOUR SAFETY IS PARAMOUNT

This is a job for a professional but if you are safety clued up, here's instruction.
Make sure the !!!!any capacitors are discharged!!!!! before attempting any sort of repair.
Check the door interlock switches first then the high voltage diode with either an AVO model 8 or moving coil meter on high resistance range for short circuit, (DVM's won't show the fault!), the capacitor can fail and go short circuit, the feed fuse on the primary of the high voltage transformer and then finally, the magnetron is best checked by substitution.
Hope that helps.

The magnetron may have either failed or is not being supplied with the extremely high voltage required to run it.

The cooling fan and turntable motor get their supply from the same point as the main transformer. If the magnetron or diode has failed that will cause excess current to be drawn and take out the supply fuse.
Make sure the !!!!capacitor is discharged!!!!! before attempting any sort of repair.
Check the door interlock switches first then the high voltage diode with either an AVO model 8 on high resistance range for short circuit, the feed fuse on the primary of the high voltage transformer and then finally, the magnetron is best checked by substitution.
Hope that helps.

http://www.givemefile.net/smanuals/_microwave_ovens/sanyo/file/6419.html
http://www.repairfaq.org/sam/micfaq.htm
OK above is a service manual, this should get you into the "ball park" I have given you also a DIY repair of microwaves.
Usually, the magnetron, or High Power Diode, is what fails. Anyway perform the troubleshooting steps, and you should be able to sort it out.
BE CAREFUL. Microwaves are LETHAL.

Sounds like a component failure in the microwave circuit.

It will be one or more of the following -

Fuse
Diode
Capacitor
Transformer
Magnetron

Reply back and I can help you more. These failures happens to new or old microwaves.

When you hit Start to cook, do the inside light and turntable come on?

Any unusual noises? Is it louder or quieter than usual?

These answers will help me judge whether it's in the high voltage section (magnetron, transformer, or diode) or the control section (door switch or control board relay or connection).

Generally, the most common causes of a failure to heat are:

- bad door switches or door switch mounts
- loose connection at the magnetron
- problem or loose connection on the control unit circuit board
- bad magnetron or other high voltage part (such as a shorted diode)

If it's a bad magnetron and your unit is within the magnetron portion of the warranty (usually 5-9 years) but out of the original full warranty (usually 1 year), then your manufacturer will cover the part cost, but not the cost to visit you or the labor charge to do the work.

If you or someone you know decide to look into it, we have critical safety information, info on door switch diagnosis and replacement, and disassembly information at our site, and our link is at our listing here on FixYa: http://tinyurl.com/yzjozk

We're happy to help and we appreciate your thoughtful rating of our answer.

If you or a friend decide to work on it, we have *critical* safety, disassembly, and troubleshooting info at our site, and our link is at our listing here on FixYa: http://tinyurl.com/yzjozk

A microwave can be dead for many reasons.

If it goes dead for a while during or after cooking then comes back on, the magnetron is probably overheating and causing the magnetron thermostat to open. Then when it cools, it closes the circuit and allows power through again.

If it's intermittent or random, it may be a bad connection, usually on the control board or a loose fuse holder.

If it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.

If it went dead a few seconds after pressing the Start pad, that's usually a failing high-voltage transformer.

If it goes dead or blows the breaker when you plug it in or open or close the door, then there's a problem with a door switch or door switch mount.

If the fuse is good, it may be an open thermostat or thermal cutout on or near the magnetron or on top of the cavity / body of the oven.

We're happy to help and we appreciate your thoughtful rating of our answer.