Replace light bulb.

if this is a standard edison base bulb try this fix. make sure power is off to oven, remove bulb, find the small tang in the base that contacts the bulbs center base and using needle nose pliers bend it up slightly, install new bulb. let us know how this works for you:)

You know how when you turn on a regular light bulb and it burns out with a bright flash? What happens is that when the filament burns out, it breaks and bounces back and hits the other electrical post and basically shorts out causing that bright flash. Sometimes, when 1 of the light bulbs in the microwave burned out, it shorted out, and caused the circuit-board trace to burn up. (This is not just conjecture; I've seen it.) If that's the case, then you would have to replace the main control circuit board. A rather expensive repair for no lights. BUT BEFORE YOU DO THAT, get an ohmmeter and check your new light light bulbs and make sure they are really good. Also, if you can, get a bright flashlight and check the light bulb sockets in the microwave (unplug it first). Check for possible corrosion or signs of arcing on the center electrode of the socket. If that's the problem, you might be able to use a small screwdriver to scrape off the corrosion of the socket (make absolutely sure you have your microwave oven unplugged before you do that!).

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

You know how when you turn on a regular light bulb and it burns out with a bright flash? What happens is that when the filament burns out, it breaks and bounces back and hits the other electrical post and basically shorts out causing that bright flash. Sometimes, when the light bulb in the microwave burned out, it shorted out, and caused the circuit-board trace to burn up. (This is not just conjecture; I've seen it.) If that's the case, then you would have to replace the main control circuit board. Unfortunately, a rather expensive repair for no lights. (Although the circuit board trace can usually be repaired by direct-soldering a wire to replace the burned trace. Sears repairmen won't do this, but an independent electronic technician could do it.

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

You need to remove the top cover to access the bulb. That is the only way on most microwaves.

That's covered on pages 35 & 36 of your owner's manual.

If for some reason you don't have yours, you can download it here.

Cooktop Light/Night Light

On models JVM1850, JNM1851, DVM1850 and
EMO4000, replace the burned-out bulb with a 120 volt,
40-watt incandescent bulb (WB36X10003), available
from your GE supplier.

On models JVM1870, JVM1871, JVM2050 and
JVM3670, replace the burned-out bulb with a 120 volt,
20-watt halogen bulb (WB36X10213), available from
your GE supplier.

To replace the bulb(s), first disconnect the
power at the main fuse or circuit breaker panel
or pull the plug.

Remove the screw at the left edge of the light
cover and push on the right edge of the cover
to open.

Be sure the bulb(s) to be replaced are cool
before removing. After breaking the adhesive
seal, remove the bulb by either gently turning
(for models JVM1850, JNM1851, DVM1850 and
EMO4000) or pulling straight out (for models
JVM1870, JVM1871, JVM2050 and JVM3670).

Replace with the same size and type bulb.

Raise the light shield and replace the screw.

Connect electrical power to the oven.

Oven Light

Replace the burned-out bulb with a 120 volt, 20-watt
halogen bulb (WB36X10213), available from your GE supplier.

To replace the oven light, first disconnect the
power at the main fuse or circuit breaker panel
or pull the plug.

Remove the top grille by taking out the screws
on top of the grille that hold it in place and
sliding the grille to the left (opening the door
makes grille removal easier).

Next, remove the light cover.

On some models, the light cover is located
in the center of the top opening. Remove the
screw that secures the light cover and lift the
cover off.

On some models, the light cover is located at the
left of the top opening. Lift the cover off.

Pinch the clips that hold the light socket in
place and lift the socket out.

Remove the bulb from the light socket by
pulling straight out. Replace with the same size
and type bulb, then replace the light socket and
cover.

Replace the grille and screws. Connect electrical
power to the oven.

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

That's on page 33 of the owner's manual. If you've misplaced yours, it's archived online here.

Cooktop Light/
Night Light

Replace the burned-out
bulb with a 40-watt
incandescent bulb
(WB36X10003), available
from your GE supplier.

1 To replace the bulb(s),
first disconnect the power
at the main fuse or circuit
breaker panel or pull the
plug.
2 Remove the screw from
light cover and lower
the cover.
3 Be sure the bulb(s) to be
replaced are cool before
removing. After breaking
the adhesive seal, remove
the bulb by gently turning.
4 Replace the screw.
Connect electrical power
to the oven.

Oven Light

Replace the burned-out
bulb with a 40-watt
incandescent bulb
(WB36X10003), available
from your GE supplier.

1 To replace the oven light,
first disconnect the power
at the main fuse or circuit
breaker panel or pull the
plug.
2 Remove the top grille by
taking out the 2 screws
that hold it in place.
3 Next, remove the screw
located above the door
near the center of the
oven that secures the
light housing.
4 Replace the screw.
Connect electrical power
to the oven.

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

That's covered on pages 35 & 36 of the owner's manual here.

Cooktop Light/Night Light

On models JVM1850, JNM1851, DVM1850 and
EMO4000, replace the burned-out bulb with a 120 volt,
40-watt incandescent bulb (WB36X10003), available
from your GE supplier.

On models JVM1870, JVM1871, JVM2050 and
JVM3670, replace the burned-out bulb with a 120 volt,
20-watt halogen bulb (WB36X10213), available from
your GE supplier.

To replace the bulb(s), first disconnect the
power at the main fuse or circuit breaker panel
or pull the plug. *

Remove the screw at the left edge of the light
cover and push on the right edge of the cover
to open.

Be sure the bulb(s) to be replaced are cool
before removing. After breaking the adhesive
seal, remove the bulb by either gently turning
(for models JVM1850, JNM1851, DVM1850 and
EMO4000) or pulling straight out (for models
JVM1870, JVM1871, JVM2050 and JVM3670).

Replace with the same size and type bulb.

Raise the light shield and replace the screw.
Connect electrical power to the oven.

Oven Light

Replace the burned-out bulb with a 120 volt, 20-watt
halogen bulb (WB36X10213), available from your
GE supplier.

To replace the oven light, first disconnect the
power at the main fuse or circuit breaker panel
or pull the plug.

Remove the top grille by taking out the screws
on top of the grille that hold it in place and
sliding the grille to the left (opening the door
makes grille removal easier).

Next, remove the light cover.

On some models, the light cover is located
in the center of the top opening. Remove the
screw that secures the light cover and lift the
cover off.

On some models, the light cover is located at the
left of the top opening. Lift the cover off.

Pinch the clips that hold the light socket in
place and lift the socket out.

Remove the bulb from the light socket by
pulling straight out. Replace with the same size
and type bulb, then replace the light socket and
cover.

Replace the grille and screws. Connect electrical
power to the oven.

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

* If your control board was damaged (lights won't come on, won't go off, fan or turntable not working right) after a cooktop light bulb blew or was inserted or removed while power was on, see here.

From the owner's manual:

Cooktop Light/Night Light

On models JVM1850, JNM1851, DVM1850 and EMO4000, replace the burned-out bulb with a 120 volt, 40-watt incandescent bulb (WB36X10003), available from your GE supplier.

On models JVM1870, JVM1871, JVM2050 and JVM3670, replace the burned-out bulb with a 120 volt,
20-watt halogen bulb (WB36X10213), available from your GE supplier.

To replace the bulb(s), first disconnect the power at the main fuse or circuit breaker panel or pull the plug.

Remove the screw at the left edge of the light cover and push on the right edge of the cover to open.

Be sure the bulb(s) to be replaced are cool before removing.

After breaking the adhesive seal, remove the bulb by either gently turning (for models JVM1850, JNM1851, DVM1850 and EMO4000) or pulling straight out (for models JVM1870, JVM1871, JVM2050 and JVM3670).

Replace with the same size and type bulb.

Raise the light shield and replace the screw.

Connect electrical power to the oven.

Oven Light

Replace the burned-out bulb with a 120 volt, 20-watt halogen bulb (WB36X10213), available from your
GE supplier.

To replace the oven light, first disconnect the power at the main fuse or circuit breaker panel or pull the plug.

Remove the top grille by taking out the screws on top of the grille that hold it in place and sliding the grille to the left (opening the door makes grille removal easier).

Next, remove the light cover.

On some models, the light cover is located in the center of the top opening.

Remove the screw that secures the light cover and lift the cover off.

On some models, the light cover is located at the left of the top opening.

Lift the cover off.

Pinch the clips that hold the light socket in place and lift the socket out.

Remove the bulb from the light socket by pulling straight out.

Replace with the same size and type bulb, then replace the light socket and cover.

Replace the grille and screws.

Connect electrical power to the oven.

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

Most likely you're going to have to dismount the microwave and remove the outside cover to get to the bulb. This is a fair amount of work but is not rocket science. I'm not famliar with your particular microwave, but it's probably that way. If it's any comfort to you, light bulbs are usually not covered by warranties or service contracts.

It won't hurt to run the microwave without a bulb.

The controller needs to be repaired. We regularly repair these control board assemblies for only $32.50 nationwide, and that's much cheaper than replacing the board. For safety, disassembly and other info see http://tinyurl.com/yzjozk