Microwave Surface Light Failure Consumer Electronics, Lighting, Microwave • Print this Page Link to this Topic [+3] - CDobyns - 11/02/2008 I misread the question. Thought you just wanted to access the bulbs. This posting is a little past its prime, but I thought it would beneficial to give it "closure" if I could. After a seemingly very long period of watching for the correct power control board to become available on the market at a price something less than what a whole new microwave would cost (<$100) - just such a board popped up on eBay for $49. The GE Power Control Smart Board WB27X10257 arrived this week and it literally took ten minutes to unscrew the old board and remove the integrated connectors and reinstall the new board. The moment of truth came when I pressed the surface light membrane button and voila (I love it when I get to use French), the lights both immediately illuminated! This just confirmed my diagnostic logic in trailing the problem back up into the power board.

Best I can tell, some small component or capacitor or something failed, since there was a small discoloration on the metal backside of the membrane panel, like something had arced. Just goes to show you that you most of this stuff can be fixed if you're smart enough and patient enough to wait for the right part to become available - at the right price. Hi - I have the exact same problem with a Sears Over the range Microwave Model 82509 - works fine but underside light and fan are not working. Can you buy these smart boards at a retailer or just on E Bay. And how tough are they to install. Does the microwave have to come out? If this is the exact same problem, my best guess is that there's been some failure on the power control board (PCB) - especially if the rest of the microwave is still working fine. That tells me its not a blown fuse, or at least probably not. Here's my best advice. Purchasing the PCB from the retailer will likely not be cost-effective - since it will probably sell for about $20 less than you paid for the microwave originally.

The trick is to cross-reference the primary part number, since this same part is probably used in other microwaves other than just Kenmores. After that, you can troll for the board (if you want to wait patiently) to come up on sale (eBay, whatever). In terms of the installation, that was remarkably easy. The cover, which is just the membrane, keypad and clock window, etc. , likely releases with just two screws at the top of the panel, and then lifts up and away from the microwave. The PCB is actually attached to the back of the membrane cover assembly. Did I mention that it is smart to unplug the microwave? After that there are typically three small screws that attach the PCB to the back of the panel membrane, and I recall there are two plugs - which just pop off. When I did it, it took me about 10-15 minutes. I'd just like to know how to remove the bulb! I've looked online and can't find any pictures that look like the bulb I have (w a black base) does the bulb push in a turn or...?

The model microwave we had, and the bulbs it uses are a threaded bulb base. Bonus points to CDobyns for keeping up with his own threads. I have this exact same issue with my kenmore model 721.80593401.. The underside lights stop working,but vent and fan still works. Should I order the circuit board? If you know unequivocally that the bulbs themselves are not the source of the problem - my gut instinct is to say yes. Harga Ac Portable PolytronAlthough it would be a little extra work, you could try and confirm the failure on the power control board, by pulling the control panel and disconnecting the existing power control board and examining it (the soldered connector side). Wyatt Oil T ShirtOn my board, the arcing/scorched problem where the lighting circuit had failed was readily apparent upon visual inspection. Australian Silky Terrier Cross Puppies Sale

That's an extra step, but it'll be up to you to gauge whether that's worth the trouble and the possibility of ordering a replacement board beforehand. There's no guarantee the circuit failure will be visually evident - but it's literally about a ten minute investment of effort. My best guess, based on what you've described - is that it is the power control board. My experience has been that absent some sort of application where wires exposed to movement or vibration, wiring is almost the problem. And most of these consumer products are so well-engineered any more, that they already consider movement and vibration when they're designed. If a large electrical appliance, like a microwave oven, works for an extended initial period of time - and absent some kind "event" (dropping, falling, folding, spindling or mutilating), the most like cause of a failure is going to attributable to some electrical or electronic component (fuse, resistor, etc.). It's almost never a wiring problem. Thanks for all the information.

I had a bulb that went bad and when trying to remove it the bulb broke. I tried to use a pair of needle nose pliers to take out the bulb base, but wound up breaking the plastic assy. I ordered a new one and put it in and got nothing. I am going to try the continuity test as you suggested and then begin the research to find a board. I am having the same problem, twice in one year the bulb stopped working and when I went to replace it the glass separated from the thread base. My husband says it's a fire hazard to use now but I need my light for cooking! Trying to find a solution to this issue. I've seen this situation, where the glass bulb when it is blown will sometime loose it's adhesion to the base - and pull free. I'm not sure how much of a "fire hazard" this particular situation is (a fire protection engineer at work assured me that was going to burst into flames). That said, it does cause the bulbs wires to be exposed - and that is a (non-fire) safety-related issue, that should be corrected.