[LIGardner]

Hello, I have a problem with my microwave (over the oven wall mounted double unit) JKP62G. When I opened the door to it on Friday it made a loud POP, the display went dead and I smelled an electrical burnt odor. (I had not actually turned on microwave, just opened the door). What I saw when I pulled microwave part way out: the fuse had blown, and lamp also filament blown.
So I pulled the microwave out of the cabinet enough to access the drop-down control panel. There was a nice wiring diagram and help guide (Pub. #31-0556) that was taped to inside of the box. I replaced the fuse and lamp and flipped breaker back on. No change. Display was still black. I did the troubleshooting on the door switches. Both checked out with the Multimeter resistance test: door closed 0 ohms; door open: infinite ohms.
I did the "monitor circuit" test next. Results not exactly right but close. The guide says I should see some ohms, but I see infinite ohms; door open got 2 ohms (guide says I should see zero).
The guide says regarding a blown fuse: "After replacing blown fuse and no cause for failure is found, check: 1. Monitor switch and interlock; 2. Power transformer; 3. HV capacitor."
Since I never turned oven on does this point to monitor switch and door switches even tho their continuity/resistance test looked fine?. We want to keep the microwave so we're willing to buy parts iof we can figure out which ones!! thanks, -Lytt

[AmpDraw]

Thats weird that you heard a loud pop just when closing the door but not turning it on. Loud pop and burning smell means something shorted out in there for sure, no way to mistake that. You should be able to see what shorted out by finding the burnt mark. If I had to guess I'd wonder if maybe something in the light circuit shorted out, like a wire melted to something on the inside somewhere, or at the base of the socket itself where the wires come in for the light. Dead display is not a good sign at all. Typically I'd associate what you've described to a shorted transformer, but there should have been no power to it to short till you set a time and run it.

The problem should be easy enough to find, you'll have to drop the microwave and remove the case, then keep looking to you find the obvious burnt marks that would have happened when you heard the pop and smelled the smoke.