It works even if I open or close the door.

Microwave ovens emit powerful radio waves and in general for safety reason should only be used when in perfect working order. It usually costs more to repair an older microwave oven than to simply replace it.
Suggest buy a new one.

take to Best buy

This could be the upper latch in the door. Mine stopped working just as you describe. After dis-mantling I noticed the mechanical action which should operate 3 micro-switches in the door lock was not working correctly on the upper switch when the door was closed.

This is part of the safety interlock circuit to prevent operation of the magnetron when the door is open.

Closer inspection of the door striker arm revealed a crack which allowed the top part of the arm to spring away from the upper switch which stopped the oven working.

This part is easily removed by prising the door inner trim off gently, starting at the bottom was easiest for me, then sliding the arm up against the spring tension until it slides clear of the guide grooves, finally detach the spring.

I have no idea where to get spare parts for this ASDA only branded product, so I am going to use super strong epoxy resin to repair the striker arm.

problem with switch

I have a JVM1850 White microwave-over the oven-installed 3 years ago. Last evening the unit would not turn off. The inside light and fan continued to run, however, the microwave was not working.

All the controls and functions seem to operate, but when completed, the unit remained working, as stated above, with the door opened or closed.

The drawer often stops working when it is abruptly stopped while opening and forced closed or vice-versa. To fix, simply do the following:
1) Push the draw all the way closed
2) Push the "Setup" button repeatedly until the "Open/Close ...?" appears.
3) Hold the Start Button until the time reappears in the display.
4) Repeat steps 2 & 3 three more times
5) Unplug the Microwave for 30 minutes.
The drawer is now reset. The drawer will now open electronically (automatically) either by pushing the open button on the panel or by pulling the drawer handle slightly.

Just checked the GE website. Had the same problem with my 5 year old microwave. GE website says to close and open the door quickly three times. First time I did this it didn't work. Second time I closed the door with some significant force and reopened it more quickly. Worked. Unplugged the microwave, plugged it back in, still fine.

Check those three microswitches in the latch assembly.

This is usually caused by either a bad door switch, a loose door switch mount (which are pretty simple problems to fix) or occasionally a problem on the control panel.

Even though a door switch clicks, it may still be bad inside. Its continuity must be checked.

Door switch or mount trouble can be caused by slamming the door or by opening the door while it's cooking without hitting the Stop pad first.

There are plastic mounts inside the microwave which hold the door switches and onto which the door latches lock when you close the door.

The screws on these mounts may be loose. If they get too loose, the switches will not be activated properly.

Sometimes it's a broken tab on the switch holder, allowing the switch to rotate just out of position. This tab can be hard to see, since it is under the bottom edge of the switch.

One test that sometimes helps is to gently lift up (and/or push down) on the door or handle as you try to start it. If it works or tries to work, then it's a door switch mount or door alignment issue.

If you or someone you know decide to look into it, we have critical information on safety, disassembly and door switches at our site, and our link is at our listing here on FixYa:.

You can find an authorized Panasonic servicer here. You can order Panasonic parts here.

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

control panel is hung up - replace panel and keypad.