Sharp Microwave diplay light not working

The problem is in the magnetron, "heart of the microwave oven" or the inverter board if the system is less than 7 years old.

It is usually repairable. See this site for details on getting it repaired.

I have the same problem. I am checking with Sharp for a part and the diagram on how to take the panel apart.

Not a complete answer, but may help describe problem: Our R-510B should be the same except for color, and for several years it has intermittently messed up its display. The left side two segments on the units digit won't light up. So a digit 8, without the two vertical bars on the left, comes out as a letter E reversed left to right. Any digit that uses the two left segments (traditionally labelled segments E and F when talking about 7-segment displays) comes out wrong. Every thing else works fine. I can't tell if this is your problem.
This is almost surely a bad contact at the interface between the LCD display panel and the PC board: Typically there is a "squishy" conductive strip that connects them, and I expect grease has gotten in there. If so careful disassembly and cleaning with a mild solvent should fix it. Since we can live with it, and it usually fixes itself in a few weeks, I have not got around to taking it apart.
Bob Wilson

Nope , could be dry joints or corroded pcb or defective display driver or supply ? Only can be told once opened and inspected.

The fact that the microwave and convection both do not heat indicated that the oven is in demo mode, check the user manual, otherwise it will possibly be a relay not triggering, may need a pcb replacement, check Demo mode 1st....Phil

This is a problem with the control panel assembly, and we repair these for customers nationwide with our guaranteed $39.95 service.

Feel free to contact me directly.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

William E. Miller
[email protected]
http://www.microwavedisplay.com

easy to fix you need to cut the tracks to the led lights then solder 2 wires to the leds next use a 1k resistor on one of the wires then conect it straight to the power surply just after the bridge rectifier noteing+ and -

check high voltage section, check magneatron, diodes, etc.

No need to replace the circuit board just to have it fail again!

We repair these on a regular basis for customers nationwide with our guaranteed $39.95 service.

We have critical safety, disassembly and repair information at our site, linked here on Fixya: http://tinyurl.com/yzjozk