[bouffard]

My double convection-micro oven has no power to the microwave. It turns on and the timer counts down normally, but there is no microwave heating. Any suggestions on the possible parts responsible.

[Gene]

Does the indicator light go "on" when the microwave is running?

If it does then the problem is with a part on the high voltage side - most likely the magnetron.

If it does not, then the next thing I would check is the fuse, the door interlock switch (under the left side upper oven door hinge, the primary interlock switch (the top switch on the latch assembly) and the secondary interlock switch (the lower switch on the latch assembly).

All of these switches are normally open or, another word, they should show ∞ Ohms when the door or the door latch are open and 0 Ohms when the door or the door latch are closed.

There is also the door monitor switch (under the right side upper oven door hinge). This switch is normally closed (0 Ohms with the door open and ∞ Ohms with the door closed).

To access the door switches the oven has to be removed from the cabinet for about 20".

- Here are the break down diagrams for the Thermador tri-mode oven Model CMT227N-01

Post your findings, please.

Gene.

[bouffard]

Originally Posted by Gene

Does the indicator light go "on" when the microwave is running?

If it does then the problem is with a part on the high voltage side - most likely the magnetron.

If it does not, then the next thing I would check is the fuse, the door interlock switch (under the left side upper oven door hinge, the primary interlock switch (the top switch on the latch assembly) and the secondary interlock switch (the lower switch on the latch assembly).

All of these switches are normally open or, another word, they should show ∞ Ohms when the door or the door latch are open and 0 Ohms when the door or the door latch are closed.

There is also the door monitor switch (under the right side upper oven door hinge). This switch is normally closed (0 Ohms with the door open and ∞ Ohms with the door closed).

To access the door switches the oven has to be removed from the cabinet for about 20".

- Here are the break down diagrams for the Thermador tri-mode oven Model CMT227N-01

Post your findings, please.

Gene.

The power light is not on. I took the oven out and found the fuse blown. I bypassed it temporarily and the microwave is working. I'll have to get a new fus and see if it blows again.
Thanks for the quick response. I'll follow up if I find any other problems.
Bouffard

[Gene]

Hi Bouffard,

The part number for the fuse is AP2825415 and APP has it in stock.

Gene.

[bouffard]

I bought the fuse from APP and it's been installed for about two weeks and the microwave is working great. Thanks again for the help.

[Gene]

I'm glad you were able to fix it.

Gene.

[bouffard]

Hi Gene,
Tonight, after telling you it's fixed, the fuse must have blown again. Do you think it's worth trying to replace the magnetron or should I just get out my checkbook and buy a new one. It is getting a little old, but I hate to spend the big bucks if I can fix it.
Thanks again.
Brian

[Gene]

Hi Brian,

I believe the blown fuse has nothing to do with the magnetron. I would check all the switches first.

Gene.

[Servicer]

As Gene mentioned above, check the monitor switch mounted on the right side hinge assembly. There may be an alignment issue, which can cause an intermittent blown fuse.

The Thermador number for this switch is 414529.