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rvgrandma · 04-20-2012, 12:54 PM

Yesterday our microwave died. It is a GE micro-convection oven model JVM1190BY, although I do not use the convection oven. My husband used it earlier and it was fine. When I got home I put my food in, touched pad and it died.

In older thread someone talked about thermistor - could this be the problem? My first thought was the breaker, but it was not blown. Turned it off and on after an hour - still dead. Then I thought of the board since we had a microwave in the past (in home) that went bad. I have had problems a couple times the last year of not being able to turn the fan off - I have to turn the breaker off for a few minutes to get it to turn off. That is the only problem we have had with it.

It is 12 years old. I went to GE troubleshooting and it said to check breaker, check fuse, etc. If there is a fuse, I have no idea where it is. We can't even find where it is plugged into power.

It is covered by extended warranty but when it comes to deductible vs a cheap one at Walmart - cheap wins since we only use the microwave. But, the exhaust fan is connected to the microwave, so that is the only feature I would want. And I miss my night light!

Any ideas out there?

Just Because · 04-20-2012, 01:43 PM

Any lights, fan or sign of life?

This may tell us where to point you.

rvgrandma · 04-20-2012, 01:59 PM

No - there is nothing. It is dead.

garym114 · 04-20-2012, 02:07 PM

They are plugged in. Usually it is above in the ventilation area.
The thermistor measures the temperature in convection units.
On the microwave the parts that usually fail are the magnetron, which makes the microwaves, the high voltage transformer or the diodes. There is usually a fuse but it is behind the controls.
Repair or replace? Probably replace if it is 12 years old.

Fred and Bonnie · 04-20-2012, 03:11 PM

The fellow in this video seems a little strange, however it's good information.

Troubleshooting the microwave oven, p1 - YouTube

fred

Perry White · 04-20-2012, 03:41 PM

If you convected cooked with the fan off, you probably tripped the over temp thermistor. Take the Micro down and pull the cabinet off and there should be an envelope taped to the inside with the repair instructions on it. You will see the thermistor on the schematic.

keninvic · 04-20-2012, 10:33 PM

Quote:

Originally Posted by Perry White

If you convected cooked with the fan off, you probably tripped the over temp thermistor. Take the Micro down and pull the cabinet off and there should be an envelope taped to the inside with the repair instructions on it. You will see the thermistor on the schematic.

I repaired mine. The thermistor is likely gone in yours; it is essentially a fuse that goes open once the temperature inside the microwave exceeds the value of the thermistor. 150C I think. Thermistor likely went because of another problem that requires fixing. Was your microwave making any noise before the thermistor blew? Mine had a noise like a bad fan bearing - I took it apart and found the doors that let air in/out of the oven were not operating properly because the stepper motor that controls the doors was worn out. The stepper motor was making the bad fan noise. Replacing the stepper motor ($20 for a used one) and the thermistor; fixed the problem. My GE is still working perfectly a year later. BTW, the magnetron has a 10 year replacement warranty from GE. Highly unlikely your magnetron is the problem if you have no display on the microwave.

TXiceman · 04-21-2012, 08:07 AM

Most microwaves have a fusible link in the power. If it gets too hot, it will melt. This is easily replaced.

Ken

rvgrandma · 04-21-2012, 11:58 PM

Not sure what is going on. Today my husband turned the breaker on just to see and the microwave is now working again. Have no idea what went on or if it will happen again.

Perry - we do not use the convection part of it. I used convection ovens in restaurants but this one does not cook like them. I tried it a couple of times with bad results so stick to using just the microwave part of it.

wa8yxm · 04-22-2012, 10:23 AM

Check list.

The first part of this can be done two ways.. But first FIND THE PLUG if you can, often it's in a cabinet next to the microwavfe.. If it's easy to access pull it and plug in a lamp (Trouble lamp is good) If the light lights, it is the microwave, If not, well then check the following.

Note: you can do this first and then look for the outlet if you wish.

Check to make sure you have power. I mean, do other 120 volt things work?
check your main and branch circuit breakers in the power distribution box.
IF YOU HAVE AN INVERTER does it have a breaker or two (often hidden where you can not easily see 'em on the backside).

NOTE: I have occasional issues in one junction box (The inverter's)

If all good.. then if you have not done the lamp test do it. NO light means you have a wireing fault (See my comment about the inverter j-box)

If the light works, then the problem is in the microwave.

Many microwaves have a fuse, this is usually INSIDE the case,, You will need to remove the microwave from it's cabinet and remove the outer case WEAR GLOVES

There are SHARP EDGES to teh metal in this area.

Some of them the fuse is accessable from the rear, no tools needed. (once removed from cabinet and set on a table)

The rest have a circuit breaker,, it too is usually accessable from the rear as above.

If the fuse/breaker is good.... Then it's gets into a job that is better done by someone with some technicial knowledge.. I have fixed a couple of 'em.