I have a lg microwave oven model mc-2681ds stopped working the service centre people say its circuit board needs to b replaced . coz of 6-7years old model the company doesnt have its spare circuiT.

Before you dump it, if it is totally dead with no lights or anything, I would check to make sure that the fuse inside is okay. Make sure that the unit is unplugged and turn it around and take the screws out that hold the cover in place and then remove the cover. Look for where the power cord goes into the back of the microwave and follow the black wire from the cord to wherever it ends. It should end at either an inline fuse folder or at a small circuit board. If it goes to a board, your fuse will be mounted on that board. Remove the fuse and have it checked with a multimeter set for continuity. If it is bad, replace it with the same size fuse, you will find the size stamped on one of the silver bands at each end of the fuse. It will be either a 15 amp or 20 amp fuse usually. If you put in a new fuse and it blows right away, that means you have a short somewhere and you would need to have a repair tech look at it. Hope this helps!