We have a Whirlpool under counter, over stove microwave (vented
outside). I replaced the underneath light bulb about a month back and
it quit again today. My wife was replacing it and it popped, blew the
glass bulb out of the metal socket/base, and won't work anymore. I
think that when she moved the bulb it shorted out inside the bulb
assembly and destroyed some circuitry inside the microwave. I tested
the leads to the bulb socket and there is no power there. The light
switch (soft touch button) still beeps like it's doing something when
you push it (it has three settings, off, bright, dim (night light)).
Anyone have any ideas? Please and thanks, HDK
2 possibilities: Did you put in the right voltage bulb, ie put in a
12V bulb when its suppose to be 120V?
or possible it uses halogen bulbs and touching it with your fingers
left oil on the bulb resulting it in popping.
In any event if you have no voltage at the socket, something blew
inside.
If it's anything like my Sharp OTR microwave, pretty much all the
circuitry except the high power stuff is on a single circuit board. If
something is bad on there, you either have to isolate to the defective
part, or replace the board. If that's beyond your skill set, an
appliance repair tech will probably want to replace the board. At that
point, you might be talking about the tradeoff between the repair
costs or buying a new microwave.
My Sharp has 2 bulbs, AC power is switched to them by relays
controlled by the microprocessor on the board. If your setup is
similar, and the power was shorted when replacing the bulb, it's
possible that either the relay contacts are bad, or circuit board
traces leading to or from the relay(s) could have opened up.
Jerry
This isn't a recipe-type fix. Remove the microwave from its mounting
brackets, take it apart, and see what's going on. If the trouble isn't
obvious from a visual inspection, then hopefully you'll find a schematic
tucked inside the machine and you'll be able to troubleshoot it.