Oven Repair Problems with Panasonic NN6750 Oven
Hello Youtubers, I’ve got another video for you here on microwave oven repair in Queens, NY. My microwave died. This is my second microwave, another one that’s as ancient as the hills. Almost as old as the other one, this was so old that the white — this was white at one time but due to use and ultraviolet light exposure and heat it’s turned yellow.
This one’s completely dead. As you can see from the date here, this one was made in 1990 another old classic. This one’s gone dead. I’m assuming it’s probably switches that had gone bad, were going to find out. Shall we?
See, we got the side of this unit here, and I’ve done work on this before. I changed that magnetron once, it says LG on it. It’s a Panasonic microwave with an LG magnetron. Very good.
First thing, we’re going to check is we’re going to get our meter out here and we’re going to check the fuse. See whether the fuse is blown. If the fuse is blown then I’ll know to look for short in switches and primary interlock switches.
And that beep tells me that that fuse is not blown. Secondary to the fuse is a thermal cutout. Thermal cutout’s job– oh that magnetron is warm. I bet you the thermal cutout is — what have you been cooking with it? And it shut off and then it wouldn’t start up.
I bet the thermal cutout is kind of open. Well, let’s just put the meter on here and see if it beeps. And it doesn’t beep. So, what that tells me is my thermal cutout has failed. I’m going to screw-in to cool this thing down a bit here and see whether it will reset itself.
Otherwise, I may have to coax it into resetting. Some of these units would reset themselves. Other ones, you actually had to take the thermal cutout apart and pop the little bimetallic strip back by hand. One time, they could be reset but once they trip they wouldn’t reset themselves.
I’m just going to pull this part here and see whether this is self-resetting or whether it’s one I have to reset manually. So in taking out the thermal cut out, this is the one in here, and it does not reset itself. I’ve cooled it down and it’s still open so I have to bend these two little tabs up here on the side and then I’m going to open up the thermal cutout and then I’ll show you how to reset the thing.
This is a little disc that you push with a something, a screwdriver or a something to pop. I’ll show you. Let me get this thing apart and I’ll show you how to do it. So, to open up the thermal cutout, I’ve just bent the tabs up a bit and I just need to pop it out from the holder.
And inside here, this plastic cover is actually an insulator to insulate that protects the switch from shorting out. So we’re just going to remove that for now, and we just have to, the couple of little clips on the side here, we’re just going to have to kind of spread this a little bit and this will pop through, pop down.
And as the switch comes apart you’ll find that there’s a little internal — there’s a little disc inside here, a little plate. And how this works is there’s a little button in here. You see this little button? That button is pressed.
When that button gets pressed, it turns off the switch. It opens the switch. See the contacts there when I press the button? It opens the contacts. So what happens when the disc, when it overheats? This is a bimetallic type strip and it flexes and all you got to do to reset it is to just pop it back in.
You’ll hear a little click when I do it, if you listen. Where is that lens? Okay, here it is. [Clicks] There, that little click? That is now reset, this bimetallic strip to its normal position so it is no longer pressing on that little button.
So then we take the unit, set it back in, place our heat transfer aluminum casing on it, place our insulator on the top again like this, and then once again put the top cover on. Put the little tabs through the little slots on here and we are good to go. Now if I really felt like it I could bend these little tabs over. Maybe I will, just a little bit. They’re not really necessary and if you do them too many times it will break.
It’s just to kind of hold it together. Now I can take the thermal cutout, and I can put it back in the microwave and the unit will work, until it overheats again. So let’s do that, okay? So, I’m mounting the thermal cutout again and realign the screws again. It’s important to make sure that your insulator is in place between the magnetron and the thermal cutout.
One, that provides the electrical insulation from the magnetron itself, but secondly it also reduces the rate of heat transfer because you don’t want the same tripping prematurely, right? So now, we’re going to connect the power leads here again.
And now you see if I take my meter, and I’m still in continuity mode. If touch my meter on here you’ll hear, we have continuity here, the same as on the fuse. So we know that we now have continuity and we can plug the microwave in and we shall have power. Well, there we have it. I can now set the clock on this thing. And that’s good enough for testing. Well, let’s put it on for a couple of seconds and we’re going do here and shut the — I don’t want the thing running full power because I don’t have anything in it but we’ll just put it on for a few seconds here, three seconds that ought to do it. There you go.
The unit is now working and that’s all there is to it. That’s how you fix a microwave that has had the thermal cutout trip. That’s how you reset a non-auto-resetting thermal cutout on a Panasonic microwave. Thanks for watching.