When starting to reheat a loud crack, explosion, sound occurred,

yes
just put it in and press the start button
most have a minimum of 30 seconds so when it counts down to 10 stop it and that is 20 seconds
you can reheat just about everything EXCEPT WHEAT BAGS as they accumulate the heat and can catch fire in the unit

If you have the kitchen timer set for instance for 10 minutes and it is counting down, and then you want to reheat you coffee for 2 minutes. You would hit either time cook or reheat button and enter 2 minutes ten hit start. The microwave will heat your coffee and show the 2 minute countdown for that. When done it will revert back to what is left on the 10 minute kitchen timer without missing a beat on most microwaves.

it has a fuse located behind the main control panel. you will see it after you remove the cover

We recommend the microwave is evaluated by an authorized service center by using www.panasonic.com/repair Welcome to Panasonic Online Repair

probably not
there is a glass fuse under the outer case near the circuit board
if that is blown it is from a short so you may have to take it in for a diagnosis

Sorry I can't help you but we purchased this same model 11 months ago and ours just stopped heating this week. Sure expected it to last longer than this.

GE
Microwave Fault Codes Failure
Code Condition Check/Repair F1 Open sensor, will occur below 190F of cavity temperature within 15 minutes after starting convection, combination or roast cook Check oven temperature sensor for continuity. Replace if zero or infinite ohms F2 Shorted thermal sensor, will occur if a shorted thermal sensor is detected continuously over 5 seconds on convection, combination or roast cooking Check oven temperature sensor for continuity. Replace if zero or infinite ohms

Note: It will take a minimum of 5 minutes of convection run time before F1 or F2 code will be displayed if the thermal sensor is shorted or open. F3 Shorted key panel (touch pad), will occur if a shorted key panel is detected continuously over 60 seconds Replace key panel (touch pad) F4 Open humidity sensor, will occur if humidity sensor is detected as being open continuously over 5 seconds Replace humidity sensor F5 Shorted humidity sensor, will occur if humidity sensor is detected as being shorted continuously over 5 seconds Replace humidity sensor F6 Shorted temperature probe, will occur if temperature probe is detected as shorted continuously over 5 seconds Replace temperature probe ProbEe Open temperature probe, will occur if temperature probe is detected open, or not plugged into the receptacle If probe is plugged in and "ProbE" is on display check continuity of the probe with an ohm meter. If zero or infinite ohms, replace it

If it will not CLEAR, You can try Un-Plugging it from the wall, let it dis-charge for 10min., then try . If you still have the problem, I would think your Control Panel has failed. The Control Panel is like an Electronic Controlled Switch with Pre-Programmed sections and Timers. Replacement is the only option. Sorry!

check if door is closed tightly those hooks on the door activate switches which close the circuit .if not open cover and check contacts on switches

try leaving umplugged 30 min.then try .