MH Microwave...worth fixing?

If it is a Sharp, it definitely has a fuse inside. Remover the outer cover and look for a ceramic slo blow fuse. Check it for continuity with your voltmeter.

I fixed a friend's last month.

DSDP Don wrote:
Some of them use a slow blow fuse. Do a search for the online manual and see if the fuse is easy to replace. Often it's in the front panel.

What Don said is true, I have fixed two microwaves by just replacing these fuses. The ones I replaced were a solid grey material not glass. Bought the fuses from Radio Shack for less than $5.

I had the same problem with my microwave /convection oven. There is no one that wants to work on them. The only places I could find wanted to charge a service call and diagnosis about $250.00. I said no thanks. I bought one that fit from Home Depot on line delivered free. I was lucky found the same make and model only 12 years newer. When you decide to change it drop me a line and I will give you some pointers.
Bill

That's a normal timeframe for failure. In fact, you probably got a couple extra years out of it. I wouldn't try to fix it.

We replaced ours through Home Depot. It was a convection. It fit the space perfectly. It was very heavy and awkward to remove so make sure there are two strong bodies around. Good luck! Sorry about the muffins. :(

wa8yxm wrote:
If it were a straight Microwave I would say no

But since it is a convection/microwave the answer is not as clear.

Remove it to the picnic table outside the RV

now inspect the thing,, Look for a fuse or reset button. IF you find none (I'll be surprised if you do) then...

Remove the outer cover CAREFUL there may be sharp edges the use of gloves (leather) when handling metal parts is highly recommended.
(Friend of mine read that warnign too late)

Again look for a fuse or breaker.

I have seen two of them where the only problem was a wore out fuse.. Fuses do wear out and blow for no good reason.

I have also seen burnt wires and blown diodes
And I have only worked on 4 Microwaves. (well 5 if you count the turntable motor in my DOMETIC by Lousy Goods (LG). (Replaced it with a GE part and now it works great).

Do be aware if you open up the microwave that there may be very high voltages present, possibly even after it is turned off and disconnected from the power outlet. A microwave magnetron requires a few thousand volts and a non-trivial current (a substantial fraction of an amp) to operate. These voltage and power levels can easily be deadly.

One not uncommon cause of the fuse in a microwave blowing is a dirty, gummed up, broken, or misaligned door safety switch. It's designed so that if the door is opened and the controls don't function properly, the fuse will be blown and the microwave power supply thus turned off before the door is opened widely enough to let dangerous levels of microwave radiation escape. That's not the only cause, of course, but it is a possible one and it can be not difficult to repair if it's a matter of cleaning accumulated crud out. If the door switch is broken, it should be replaced only with an identical one due to its being a safety interlock device.

In this case, a thermal fuse blowing does sound reasonably likely since the problem happened on convection cooking, not microwave cooking.

We repaired our microwave and it lasted for a while. Got a new one at about the cost of repair. When that went, we just replaced it. Newer, cleaner, less hassle. Measuring is important!

The problem with anything electronic these days is the components have been so highly customized that there usually aren't any off-the-shelf replacements. Any electronic component that's more than two years old has probably been declared end-of-life already and replaced with something else that is entirely incompatible. So finding replacement parts is almost impossible even if you knew which one needed replacing.

The good news though is the price of almost anything electronic has been dropping like a rock for years. Finding a new microwave to replace that old one usually means just finding one that fits in the space available, and the added benefit it the new one will come with more features (bells and whistles).

This is a hard lesson that I still haven't managed to learn about computers and TVs. I always try to repair or upgrade them and in the end spend more time and money than it would have cost to just replace them outright and trash the old one.

My 14 yr old sharps convection microwave died 3 weeks ago. Naturally the exact mdl is not made anymore. However I was able to order a replacement sharps from home depot. $289 slid right in. At that price I did not consider getting it repaired. The new one has many newer features.

If it were a straight Microwave I would say no

But since it is a convection/microwave the answer is not as clear.

Remove it to the picnic table outside the RV

now inspect the thing,, Look for a fuse or reset button. IF you find none (I'll be surprised if you do) then...

Remove the outer cover CAREFUL there may be sharp edges the use of gloves (leather) when handling metal parts is highly recommended.
(Friend of mine read that warnign too late)

Again look for a fuse or breaker.

I have seen two of them where the only problem was a wore out fuse.. Fuses do wear out and blow for no good reason.

I have also seen burnt wires and blown diodes
And I have only worked on 4 Microwaves. (well 5 if you count the turntable motor in my DOMETIC by Lousy Goods (LG). (Replaced it with a GE part and now it works great).

Some of them use a slow blow fuse. Do a search for the online manual and see if the fuse is easy to replace. Often it's in the front panel.