[Whee]

1997 Jenn-Air M170W. The timer works, but no heat, fan or turntable. Sudden failure.

From reading forums it looks like a door switch is probably at fault. There are three switches, so probably makes sense to replace them all. Any other parts that are likely to be needed? It's a built-in so worth spending some time to try and fix.

Also - any instructions available for how to get to the switches? The regular manual doesn't go into that level of detail.

Thanks in advance!

[Joe / APP Team]

Originally Posted by Whee

1997 Jenn-Air M170W. The timer works, but no heat, fan or turntable. Sudden failure.

From reading forums it looks like a door switch is probably at fault. There are three switches, so probably makes sense to replace them all. Any other parts that are likely to be needed? It's a built-in so worth spending some time to try and fix.

Also - any instructions available for how to get to the switches? The regular manual doesn't go into that level of detail.

Thanks in advance!

Whee,

First things first, you will need to remove the microwave from the cabinet or wall oven . All acces to the internal components are performed from the inside of the unit, and you will need to remove the outer cabinet.
Once you have the unit unplugged and out on a workbench :
A) Remove the four screws from the rear section and push the cabinet backwards.
To remove the control panel assembly:
A) Disconnect two connectors and terminals on the printed circuit board assembly. Remove screw while holding the grounding ring terminal of main harness, whichsecures the front plate.
B) Remove three screws holding control panel assembly to the oven front. At the same time, draw forward the control panel assembly fom oven front.
C) Remove the push lever.
D) Remove three screws from the control.
E) Remove push button and button spring from control panel.
F) Reverse the above steps for reassembly.
You can now access and remove the door switch mounting bracket screws, remove the two screws and slide the assembly back, then out, and replace the door switches.
The door switches are a good place to start, but you may also need the printed circuit board,

Part number: AP324449

Which has been discontinued by the manufacturer, and we are unaware of any other parts source.

Thanks and Good Luck,

[MicrowaveDisplaydotcom]

Check the technical sheet or schematic hidden inside the oven.

You can see a distorted scan of the overall schematic here. The schematic shows the door shut and oven idle.

With the symptoms you describe, your problem is going to be the secondary interlock (bottom door switch) or its mount. That switch has one or more thick white wires going to it.

If that door switch does not close, then you will get a countdown, but no turntable, lamp, or fan and it will not cook.

If the turntable, lamp, and fan did not work, but it did cook, then relay B on the board would be bad.

If the turntable, lamp, and fan all worked, but the high voltage section did not engage to cook, then relay A on the board would be bad.

Our help file on door switches is here.

If either of those relays were bad, they could be replaced.

.

[Whee]

Thanks for the very useful help. Much appreciated.

The problem was in the switch labeled 16 in this diagram. Replacement parts for JENN-AIR M170W MWAVE- MOUNTED OVER RANGE/WO | AppliancePartsPros.com

The contacts were clearly blackened. While I purchased all 3 switches, I ended up just replacing that one since they were a pain to get out.

Microwave is working fine now.

Thanks again!

[MicrowaveDisplaydotcom]

Ugh. You're right.

I realize now I didn't read your initial post quite clearly enough, so I can see how it would have been the primary interlock in this case.

It is a good idea to replace both the primary and secondary though. The monitor doesn't matter.

Oh well, maybe I kick-started you... heh

[Joe / APP Team]

Originally Posted by Whee

Thanks for the very useful help. Much appreciated.

The problem was in the switch labeled 16 in this diagram. Replacement parts for JENN-AIR M170W MWAVE- MOUNTED OVER RANGE/WO | AppliancePartsPros.com

The contacts were clearly blackened. While I purchased all 3 switches, I ended up just replacing that one since they were a pain to get out.

Microwave is working fine now.

Thanks again!

Whee,

Great,
Glad you're up and running, and you were able to get by with the door switches.

Good Luck and Thanks,

[MicrowaveDisplaydotcom]

This seems like an older model and it may have just been normal aging, but I always advise folks not to open the door while it's cooking, but to hit the "Stop" pad first.

The switches will of course stop it, but they're not designed for the heavy spark caused by inductive kickback when the load is interrupted that way.

They're instead meant as safety interlocks to prevent the oven from cooking while the door is open.

Also, slamming the door can cause the switch mounts to be misaligned or damaged.

Good cooking to you!

[Joe / APP Team]

Originally Posted by MicrowaveDisplaydotcom

This seems like an older model and it may have just been normal aging, but I always advise folks not to open the door while it's cooking, but to hit the "Stop" pad first.

The switches will of course stop it, but they're not designed for the heavy spark caused by inductive kickback when the load is interrupted that way.

They're instead meant as safety interlocks to prevent the oven from cooking while the door is open.

Also, slamming the door can cause the switch mounts to be misaligned or damaged.

Good cooking to you!

Correct on all counts,

It is an older microwave(early to middle 90's) and usually part of a combination wall oven/microwave.

Slamming the door is not good for any appliance, and is the first thing to check, whenever there is a start or run issue.

The door switch circuits are a bit more tolerant than you imply, but pausing or stopping the control is something that needs to be considderred, to help resolve an ongoing issue.

Good Luck,

[MicrowaveDisplaydotcom]

They'll put up with the arcing for a while, but it greatly shortens their lives.

I did not mean to imply that they're as sensitive as it may have come across.

[Joe / APP Team]

Originally Posted by MicrowaveDisplaydotcom

They'll put up with the arcing for a while, but it greatly shortens their lives.

I did not mean to imply that they're as sensitive as it may have come across.

We're on the same page, that's the important thing. We're here to help our customers, and each other when we can.

Later,