When The microwave shuts off (if it is electronic) does the diplay go blank also?
Please send a model number with Your response.
Ok what You have is a microwave emission leak and it interferes with the board usualy the only way to get the gasket that seals the magnetron to the wave guide is by buying the magnetron, found the part here>
Only place it came up for Me
Here I show You circled in red where the magnetron is and again in red on the wave guide to show You where it mounts>
Now for the bad news this can damage the control board I circled the control in yellow and where it mounts on the cabinet so You could see how close it is to the magnetron.
You could try to replace the Mag and gasket and see if the control still works but if it doesnt here is a link to the control>
Found the parts, be about $200 to fix worse case.
Step 1: You tell Me Your problem.
Step 2: I spend some time with You asking questions because You are My eyes, hands, and ears (in Your case i have seen this alot so I was able to make a decision quickly)
Step 3: I spend a few minutes giving You some basic information, where to get the parts, how much they will cost etc.
Step 4: You decide if it is economical for You to repair it or replace it, in Your case a $200 repair on a $179 dollar microwave (this which I knew) This is where most people will say " I would probably just be better off buying a new one " I gave nothing more than facts this decision is made on thier own.
Step 5: Either We are done or you want to get the parts if You where going to fix it all you had to do is tell Me and Thats when I would spend the 45+ minutes giving detailed instructions on replacing the parts, Why would I do this up front when there is a good chance You wont even fix it?
If Your not going to fix it and go buy a new one Why would it be even necessary to type all that out.... I am not given any thing here except a way to comunicate with You I use My own materials, resources, and experience to guide My customers in doing repairs on thier own.
If You feel You have been had ask for a refund.
If My diagram was insufficient to do the repair, YOU should of asked for more details I have no clue how much or little you know and I can answer a lot more questions if I am not wasting time typing out instructions for someone I have no clue will even use them.
As far as if the part will fix it I am coming up on My 20,000 in home service call at My primary job and I can honestly say that close to 50 have been Your same problem.
You have a nice day!