microwave suddenly very weak, but heats, slowly

Microwave Repair
1

Bought a house with a kems307gbl0 microwave / oven combo.

initially, worked great. Now the microwave takes forever to heat anything… 5-6 minutes for popcorn (was 2.x minutes before), heat a slice of pizza 2-3 minutes (was <1 minute).

Wasn’t sure if this is a magnatron issue or something else.

Thanks for any help

Paul

3

Hi, Paul.

You are absolutely right - it’s got to be the magnetron:

AP4412010

Here are the breakdown diagrams and parts list for your microwave:

[MODEL]KEMS307GBL0[/MODEL]

Good luck. Please keep us posted with the results.

Thank you,

Simon.

4

Simon / APP Team said:
Hi, Paul.

You are absolutely right - it’s got to be the magnetron:

AP4412010

Here are the breakdown diagrams and parts list for your microwave:

[MODEL]KEMS307GBL0[/MODEL]

Good luck. Please keep us posted with the results.

Thank you,

Simon.

Thanks. That was my initial go to guess… of course…reading everything online… elsewhere, someone mentioned it might be a thermal cut off or bad thermostat or something over heating that just might need to be cleaned… my spidey sense still leads me to the magnatron, where the unit is 15 years old.

Is there any tip or trick to getting to the mag in this particular model, short of just hunting and pecking til I find it?

Just wanted to be sure that it was most likely the magatron, before dropping $126 on the part.

5

Hi, Paul.

First of all we have a return policy that allows you to return any parts you don’t need for full refund within one year.
There is no any special trick to make your life easier :(. You will have to lift of the console, remove the top and bottom grills, remove two screws holding the unit at the bottom one on each side and then slide the unit out. Be careful with wires, disconnect them all after memorizing where they go (take a picture). Oh, and don’t forget to turn the breakers off!!!

Good luck.

Thank you,

Simon.

6

Simon / APP Team said:
Hi, Paul.

First of all we have a return policy that allows you to return any parts you don’t need for full refund within one year.
There is no any special trick to make your life easier :(. You will have to lift of the console, remove the top and bottom grills, remove two screws holding the unit at the bottom one on each side and then slide the unit out. Be careful with wires, disconnect them all after memorizing where they go (take a picture). Oh, and don’t forget to turn the breakers off!!!
Good luck.

Thank you,

Simon.

Thanks once again…

So no problem returning a part that was installed that didn’t fix the problem. I normally don’t like randomly replacing parts, but as long as I can return it, that takes some of the pressure off.

7

Give it a shot.

Thank you,

Simon.

8

Thanks. Got the magnetron installed. seemed to help a bit, but still seems to heat slowly…

if I make, say, popcorn, it takes about 4-5 minutes to get 1-2 pops a second, then half the bag is burnt, and half unpopped. If I use the popcorn button, about, or over, half the bag is unpopped.

The microwave ‘hums’ for about 15-30 seconds…then stops humming for about 10-15, then hums again (repeats) I assume the humming is the magnetron engaging.

Thoughts to something else being the problem? Any heat or safety sensor that could be failed or weak?

9

any idea on my post above?

Thanks

Paul

10

some more info:

hums (cooking i assume) for 17-18 seconds, then no humming for 3 seconds… over and over

think it could be a bad replacement magnetron? or something else?

11

My microwave is doing the same thing or similar. It’ll cook food but not pop popcorn. I also cant adjust the power setting.

I’ve rea it can be a bad triac. Have you tried that? I thinking ill test it out on mine to see if its bad.

12

I replaced the magnetron as i said above, which didn’t seem to fix it, although did make it marginally better.

Since I didnt get a reply here, I chatted with them. They suggested I replace the high voltage transformer

I replaced it today, and it seems better. I haven’t put it through its paces, but it works without the humming

13

Just an update. Hum came back. The transformer did not fix it. Basically replaced every part - still not working.

Finally replaced the control panel - got it off ********, NOS, as the unit has been discontinued for some time. There are companies that will repair the circuit board, but I did score one.

This seems to have fixed the problem. Apparently the relay on the circuit board was bad/wore out over the years

Been working great for the past few weeks, so I am 99% sure it is fixed.