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Need help please Microwave control pad doesn't work!!!

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hockey4ever

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Hello,
My "over the range" micro-Wave Samsung SMH8165w doesn't work anymore. It all began when we put the french fry cooker under the microwave. Microwave touch pad received all the steam from the cooker. (sometime we do stupid thing) Since then, start button doesn't work. If we press on the number, the microwave is responding... It is responding also if we press the light button. It doesn't respond when i press on start, on fan button and any cooking mode button. I suspect the micro-switch pad to be defective. Do you think the steam burned those micro-switches? Thanks for your help!!!!
 
Most microwaves's don't use micro switches, it's a membrane keyboard, they're generally immune to moisture. It's not recommended (and could be very hazardous) to open it up and try to clean the keypad out, IF that is in fact the case, it could be the actual control electronics that are effected in which case it's probably not recommended to attempt a repair unless you know exactly what you're doing, the voltages possible from a microwave are VERY.
 
It's almost certainly the membrane keypad, they are VERY unreliable devices.

It's a question of sourcing one as a spare part and replacing it, assuming it's available, and that you can get hold of one.

It might be that you can only buy a complete electronics assembly, or that you can't get spares at all - certainly in the UK you can only get microwave spares if you're an approved agent.
 
If there's not too much button's on it, it might be possible to figure out the multiplex and mock up your own keypad with buttons. It won't look nice but it works - done it before myself.
 
I'm going to make a few comments here. One is the arrangement of the keypad. Is the effect related to a particular row or column?
 
Problem Solved!!!!! WOOHOO!!!!!!!!

My wife solved it! She found on the Samsung website a FAQ section regarding this particular microwave model. There was a faq on "demo mode" wich intrigued her. She followed the directions on how to disabled that "demo mode" and BINGO!!!!! It came back alive!!!!! For some reasons the microwave switched to demo!!!!!! So tx again for your help!!!!!
 
Someone held a button down for too long =)

Nigel, before you say you're sure of something and state that membrane keypads are unreliable, keep in mind they're used on a VAST array of devices, they're just not meant for extreme duty use, for a microwave the chances of one wearing out are VERY low, we had scales at work that used membrane keypads and they failed roughly every two years, but this was for a button that was hit 500-1000 times a day, and it was in a very caustic environment. Typical membrane switches are extremely reliable in the correct environment.
 
This is how ive repaired touch pads. They are a carbon condutive surface on the rubber pad & do wear. Just paint the non working one with silver based conductive paint. The one i use is used to repair rear window heater strips.
 
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