GE Microwave working Intermittantly

[aviat0r]

Hi, I've got a GE Profile Microwave model PEB1590SM2SS that is working intermittently. It usually works if it hasn't been used for a while but if it is used several times in a row it doesn't heat. Light comes on, Table turns etc but no heating. If I then try the "Sensor Cook" option, sometimes after it runs for a short time you can hear something else turn on inside the oven and it does cook.

Thanks

[HayZee518]

microwave

I would look toward the door latches microswitch first. there are several safety devices that must make up before the magnatron turns on.

[aviat0r]

Thanks, If it is a door switch, how does it work when the sensor cook option is used?

It seems to konk out when it gets warm from use or even when things are warm from the oven installed beneath it being used. Is there a component that is heat sensitive?

[Dan O.]

Intermittent problems are the hardest to pinpoint. The main problem is that it will have to be investigated while the condition is present to test for possible causes.

One of the first things to try is addressing the door switches as HayZee518 suggested. When it occurs again try opening and then firmly (not gingerly) closing the door and then try restarting it. Door switches can get 'sticky' with age and cooking residue which could delay opening or closing of its contacts. A firm door close will make sure the switches activate together if they are able.

Is there a component that is heat sensitive?

There is at least one thermal cut out (TCO), mounted on the magnetron tube. There are sometimes others but I don't see any listed in the parts list for your model but any others should be shown on the unit's wiring diagram.

LINK > GE PEB1590SM2SS Thermal Cut Out

If the magnetron tube was overheating, the TCO would open and cut out power to the magnetron tube, preventing heating but the rest of the machine would still function normally. I can't see how sensor cooking would be any difference with that failure. Maybe the operation was just a coincidence or the tube had a chance to cool by then and the protector close again? I don't know if it is a one-time cut out (non-resettable, that would need to be replaced once tripped) or one that would reset on its own once cool.

A problem with the cooling fan might cause the magnetron tube to overheat, as could a problem with the magnetron tube itself. Blocked air vents at the rear could cause overheating. Is the unit built-in in any way?

LINK > PEB1590SM2SS Cooling Fan

LINK > PEB1590SM2SS Magnetron Tube

If setting the control to sensor cook does in fact allow the unit to heat, the only thing I can think of that might be responsible is the unit's electronic control. A failing control could be susceptible to ambient heat.

LINK > PEB1590SM2SS Electronic Control aka 'Smart Board'


JMO

Dan O.
Appliance411.com
The Appliance Information Site
=D~~~~~~

.

[Jim-Martin]

Here's my experience with a Magic Chef microwave

I had this happen with a Magic Chef built-in microwave.

Same thing, would work 4-5 times in a row and then now heat.

The home builder took some short cuts and did not properly vent the unit. I guess it was getting too hot and not turning on.

Ultimately, I solved the problem by cutting holes in my cabinets and properly venting the unit.

Jim Martin

Dallas Air Conditioning Service | Dallas AC Repair Service | Dallas Heating Service | 24-hour HVAC Technicians

[aviat0r]

Dan,

Yeah I've tried slamming the door and it doesn't seem to have any effect on it working....Also the fact the the door isn't touched when it gets itself working off of the sensor cook function leads me to believe one of the other parts is the problem

The unit is built in over the stove so i do suspect that has something to do with it....It is more likely to not work after the stove has been on...I just don't know which part is susceptible to the heat. It does have the fascia that is designed to work with the microwave to vent it.



Thanks

[HayZee518]

sensor

then I would try what Dan O suggested. Look for a temperature sensor on the magnetron. it may look like a "klixon" overload - a small can with spade terminals on it.
another thing is a thermister across the line input of the power supply. looks like a red disk. as it heats up its resistance changes

[aviat0r]

Thanks guys. I will update with any progress

[aviat0r]

It was the Smart Board....my guess is since it's built in the heat built up and damaged some component on the board....

[Dan O.]

Fixed!

It was the Smart Board.

Glad to hear you found the problem. Thanks for the follow up.

my guess is since it's built in the heat built up and damaged some component on the board....

That could be a possibility.

Dan O.
Appliance411.com
The Appliance Information Site
=D~~~~~~

.