Sharp Carousel R-1470A Over the range microwave- doesn't have power. Circuit breaker in basement and outlet is fine - I can unplug microwave and plug in another appliance and it gets power. Now what?

Take the body cover off and locate the regular glass fuse near the control panel wiring and make sure the fuse is good. A blown circuit breaker is the first clue that the fuse could have also blown.

I have rescued tons of microwaves for the lack of a 50 cent fuse.

internal short will do that
could be a transformer or magnatron

Hello Anonymous

At the risk of starting with the very basics, when you say that the clock and panel aren't lit and wont' work at all, the first place to look is the wall power. You may be missing power from the wall because:

1. The microwave isn't plugged in. Someone may have yanked a plug to plug in a mixer, phone charger, thanksgiving animated ornament, or what have you. Trace the cord back and make sure it's plugged in.
2. Make sure the outlet has power. Take some plug-in-able item and plug to the outlet and see if it can turn on. If not:

1. A number of kitchen outlets may have GFI switches, especially if they are anywhere near sinks. The GFI may have been tripped. There should be a reset switch in the middle of the plug. See if it's tripped, and reset if necessary.

2. The breaker may have been tripped. Most kitchen circuits are wired to 20Amp breakers. If this is elsewhere in the house, like in an entertainment room or such, it is likely a 15 Amp outlet. Microwaves can draw a fair amount of power. Someone using another kitchen appliance, hair dryer, or what have you, on the same circuit, may have tripped the breaker. Newer code may specify an AFI or GFI breaker for kitchen outlets. In that case, a fault with something else on the circuit may have tripped the breaker. If that is the case, and it trips again, talk to an electrician. You don't want a fault like that undiagnosed.
   
   3) You may also want to try plugging the microwave into another outlet, even if the normal outlet seems OK
   
   If there's wall power and a good plug-in, then you work back to the microwave itself. A number will have fuses. Also, there may be interlocks that kick in if, for instance, the carousel rotation is impeded - that can mean something on the carousel is hitting a wall, which can risk tipping something over and spilling, or risk mucking up the reduction gears for the carousel axle if it keeps pushing.
   
   At that point, looking for specifics on your microwave model will be needed. You may also try the Microsoft Support approach - i.e unplug it for 5 minutes, then plug it back in and see if it works.
   
   Hoping this helps, Good Luck!
   

Steve,
You probably have a blown fuse.

Unplug your microwave and turn it around and remove the screws holding cover on and then remove the cover. Look for where the power cord goes into the back of the unit and follow the black wire from the cord to where it ends. It should stop an either a circuit board or a fuse holder. Make sure that you replace the fuse with the same amperage fuse as what you take out. You will find the amp rating stamped on one of the silver collars on each end of the fuse. Good luck!

Conact manufacturer and they will advise.

>> We also tried plugging our toaster into the microwave plug outlet, and the toaster wouldn't work in that outlet, but worked just fine in a different outlet in the RV.

This means the outlet you plug your microwave into needs to be fixed in addition to fixing the oven. Breaker? Fuse?

>> I understand from another RV forum that microwave ovens for RVs have "special circuitry and cooling features" not found in regular countertop ovens for household use.

Not really in my experience. Any microwave supplied with clean AC power and proper venting space will be fine.

But I'd bet your microwave can be fixed affordably.

The main internal things which can result in this model being dead (no display, no light when you open the door, no beep when you press a pad on the keypad) would be the 20A fuse and the magnetron temperature fuse. There could also be bad connections on the noise filter board.

Also, sometimes a power surge can cause the power to be interrupted to the low voltage transformer on the board, and I regularly repair those boards. I can also write a technical statement to your insurance company or to an RV park as needed.

At my Web site, I have a video available showing how to remove a typical over the range control panel assembly in under 5 minutes.

The relevant service manuals for this model are here and here.

You can order Sharp parts from Sears or Encompass.

Contact me directly if you need more help.

- William E. Miller, AS-EET
[email protected]
http://www.MicrowaveControl.com
Microwave Oven Control Panel Repair Nationwide "Recycling by repairing since 1982"

Hello

Plug the microwave into the outlet if the microwave won't power up. Make sure the plugs on the microwave match the type of outlet. A four-pronged outlet can only be used with a four-pronged plug. Same with three-pronged outlets---they only work with three-pronged plugs.


Inspect the plug. Make sure it hasn't been cut or tampered with. Four-pronged plugs can't be cut down to fit a three-pronged outlet. Three-pronged plugs mustn't be forced into four-pronged outlets. A three-pronged plug mustn't be used in a two-pronged outlet, either.


Replace blown fuses, or if there's a circuit breaker, check it for tripped breakers. Sometimes the trip won't be obvious, so cycle the circuit breakers. Turn them all the way off and then back on again.


Plug another appliance in the outlet. You will find this easier with three-pronged appliances. Simply plug a toaster, or other appliance into the microwave's outlet, and see if it works. If it works, you know the problem is with the microwave, not the power circuit. Have the microwave serviced or replace it. If the toaster or other appliance doesn't turn on, you know the problem is with the circuit.

1. Plug the microwave into the outlet if the microwave won't power up. Make sure the plugs on the microwave match the type of outlet. A four-pronged outlet can only be used with a four-pronged plug. Same with three-pronged outlets---they only work with three-pronged plugs.

2. Inspect the plug. Make sure it hasn't been cut or tampered with. Four-pronged plugs can't be cut down to fit a three-pronged outlet. Three-pronged plugs mustn't be forced into four-pronged outlets. A three-pronged plug mustn't be used in a two-pronged outlet, either.

3. Replace blown fuses, or if there's a circuit breaker, check it for tripped breakers. Sometimes the trip won't be obvious, so cycle the circuit breakers. Turn them all the way off and then back on again.

4. Plug another appliance in the outlet. You will find this easier with three-pronged appliances. Simply plug a toaster, or other appliance into the microwave's outlet, and see if it works. If it works, you know the problem is with the microwave, not the power circuit. Have the microwave serviced or replace it. If the toaster or other appliance doesn't turn on, you know the problem is with the circuit.
Hope i could help you.
Have a nice day : )

Hi,
Here is a tip that will help you to figure out what is wrong with yourMicrowave Oven....

Microwave Oven Basic Troubleshooting Tips

heatman101

sghg

There are a couple of safety thermostats in the oven to shut down power if something overheats. One is on the magnetron tube (the microwave source), the other is on the cooking cavity. These sometimes go bad. There's also a power line fuse that may have failed, or become loose in its mounting clips. These can be tested with an ohmmeter; they should all measure very close to zero ohms if they're good.

Another possibility is that the control circuit board in the oven may have failed. I have worked on several Sharp ovens where the power transformer for the board has gone bad for no good reason. If the board goes bad the oven may appear to be dead as well.

Microwave servicing is best left to professionals. If you're thinking of keeping this one, take it to a service shop (or call for home service) and get an estimate. Then decide whether to repair or replace.

Hope this has helped a little. Thanks for using Fixya!