My microwave will not start at all, instead I just have flashing 88:88 in the display panel. Could it be a blown fuse?
No! this indicates a keypad control board issue.
SOURCE: R-4H84 Sharp Carousel II microwave oven stoped working
A microwave can be dead for many reasons.
The fuse is normally located on the floor of the chassis behind the control panel or between the door switches.
If the fuse is good, it may be an open thermostat or thermal cutout (TCO) / thermal fuse on or near the magnetron or on top of the cavity / body of the oven.
If it goes dead for a while during or after cooking then comes back on, the magnetron is probably overheating and causing the magnetron thermostat to open.
Then when it cools, it closes the circuit and allows power through again.
When checking thermostats, if it has a hood fan thermostat, that should read open, as opposed to the others, which should read closed.
If it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.
If it went dead a few seconds after pressing the Start pad, that's usually a failing high-voltage transformer.
If it goes dead or blows the breaker when you plug it in or open or close the door, then there's a problem with a door switch or door switch mount.
If it's intermittent or random, it may be a bad connection, usually on the control board or a loose fuse holder, or even an intermittent fuse.
You should do a continuity test on the fuse while it's in the holder (with the microwave unplugged, of course) then turn the fuse by hand or take it out and put it back in, then test it again.
If you remove the fuse, then press the meter leads against the ends, it can allow internal contact to be made and make a bad fuse appear to be good.
If you or someone you know decide to look into it, we have critical safety information and disassembly information at our site, and our link is at our listing here on FixYa: http://tinyurl.com/yzjozk
We're happy to help and we appreciate your thoughtful rating of our answer.
SOURCE: my Sharp carousel model R-306LW
We have the service manual for this model and have uploaded it to our site here to help you.
You will need the free Acrobat Reader to view or print it in case you don't have it already.
I would bet that the high voltage capacitor shorted and took out the fuse. It may possibly be the high voltage rectifier diode, but I bet it's not.
Here are some additional links you or someone you know can use (in order given) for test help, but read the safety warnings first:
http://www.gallawa.com/microtech/cap_test.html
http://www.gallawa.com/microtech/diode.html (if it is NOT shorted, it's probably fine)
The best place to order Sharp parts is Tritronics.
We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.
SOURCE: I have a sharp carousel
On this model, the fuse is located between the door switches.
But a microwave can be dead for many reasons.
If it goes dead for a while during or after cooking then comes back on, the magnetron is probably overheating and causing the magnetron thermostat to open. Then when it cools, it closes the circuit and allows power through again.
If it's intermittent or random, it may be a bad connection, usually on the control board or a loose fuse holder, or even an intermittent fuse.
You should do a continuity test the fuse while it's in the holder (with the microwave unplugged, of course) then turn the fuse by hand or take it out and put it back in, then test it again. If you remove the fuse, then press the meter leads against the ends, it can allow internal contact to be made and make a bad fuse appear to be good.
If it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.
If it went dead a few seconds after pressing the Start pad, that's usually a failing high-voltage transformer.
If it goes dead or blows the breaker when you plug it in or open or close the door, then there's a problem with a door switch or door switch mount.
If the fuse is good, it may be an open thermostat or thermal cutout on or near the magnetron or on top of the cavity / body of the oven.
Before you look into it further, we have critical safety information and disassembly information at our site, and our link is at our listing here on FixYa: http://tinyurl.com/yzjozk
We have the exploded view and wiring diagram at our site. They will help you locate and test the parts.
http://207.234.249.73/mwd/r1470_exploded.jpg http://207.234.249.73/mwd/r1470_wiring.jpg
Feel free to reply back if you need more help.
We're happy to help and we appreciate your thoughtful rating of our answer.
SOURCE: Sharp microwave oven LCD display malfunctions
Might or might not work. IT worked for me.
This is a common problem. i havent completly solved it yet but this helps.
Be very careful doing this, There is Voltages with AMPERAGES high enough to boil your blood inside a microwave.
I had mine apart cleaning it. Only one number worked on my display. I wiggled and messed around with the wires in the back of the display. And almost every number in the display works again. Hope this helps.
SOURCE: Hi our Sahrp Carousel microwave LCD panle display is not working
You have to replace the control board. Sharp has had problems with the display boards for awhile. There is no bulb or fuse you can change.
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