Hey, first time poster here. I hope this is the right place for this thread, it was a tossup between here or the Technical Stuff forum.
So I was visiting my grandparents earlier today and they're having some appliance woes. Their stove, a Kenmore, which is probably old enough to drink in certain countries, has an LCD display (or perhaps VFD?) that works sometimes and not others. It randomly fades in and out like someone is messing with the alpha slider in photoshop.
Here it is working:
![](http://i.imgur.com/UgIgFl.jpg)
Here it is, about a minute later, not working at all (as one might expect):
![](http://i.imgur.com/Rew1el.jpg)
Afterwards, it wobbled somewhere at around half brightness before coming back.
I know quite a bit about electronics - I'm studying to be an EE - but aside from some hunches I don't know for sure what's wrong. I don't want to take it apart without a pretty good idea, since it will leave them without a stove. My first hunch was that the LCD/VFD is simply wearing out, but I guess if that were true, it would just stop working and stay that way. This one comes back to life as if nothing ever went wrong. And even when the display is dead, the buttons and controls still work perfectly - including the little piezo buzzer that beeps whenever you push a button. So I doubt it's a microcontroller issue.
My current hunches are dying capacitors or power supply. I'm hoping it's the former since it's $1 of parts, a soldering iron and an afternoon. If it's the latter, I'm hoping it's just a regulator on the board I can replace, otherwise I'm not too comfortable messing with the electricals of someone's stove.
Oh, and Sears wants $800 to fix it. lol.
So, does anyone have any ideas what could be busted? I have no idea what the model number of this stove is, so I don't have any technical docs, if they even exist. I'd appreciate any help. Anything to avoid them having to eat
eight hundred dollars. If that's the only option, then I told them just to put it towards a new stove.