Topic: Microwave Poltergeist or planned obsolescence.....

[NJAntman]

About an hour ago the microwave oven just turned itself on, apparently running a full 4 minute full power cycle. I stared at my wife, she at me, we both looked at my 5 yr old son and asked/accused "Did you touch the microwave?". I went in and pressed the OFF/CLEAR button, it kept on going so I opened the door and it stops. Close the door, it starts right back, open - stop, close -start. OK. Tried all the buttons, no change and no response, so put a big bowl of water in and let it finish the run. It did, and then the display went out, no clock, no response from hitting any button. Huh?

So there I am looking at it about a minute later and presto, turns itself back on. Same deal, 4 minute run at full power, no response from any control pad buttons. I pulled the power cord, plugged it back in about a minute later. Normally after a power failure it will display "RESET" and bring up the clock for adjusting. This time after plugging back in the control display showed all the possible character combinations at once for about 10 seconds, then "RESET" came up, then presto, right back into a full 4 minute full power cycle. WTF!!

Well now, I try the control pad, no response. Open - stop, close - start. Pull the cord again, wait 10 minutes. Plug it in, presto, right back to a full 4 minute high power run. Once it finishes the only control pad response I get is clock reset, but it only chooses the number 4 for whatever key I press; and blissfully after about a minute it starts again with a highpower 4 minute run.

Obviously its FUBAR, but now I'm curious. Is this planned obsolescence in a 6 yr old appliance? Seems a mighty dangerous way to get the message across to go forth and buy another if the previous one randomly turns on until burning down the house (damn glad we were here when this happened).

Or is this just a friggin electronic Poltergeist, happy to ruin a fairly decent Sunday morning?

[NJAntman]

Alrighty, turns out to be a poltergeist. Reply from GE tech support says I should have waited 30 minutes unplugged to "clear out the memory". Sure enough, after a whole day unplugged it know seems to be working again (plugged in that is).

OK you electronic techs, just what how in the hell does a Microwave keep "bad memory" for ten minutes?

[Sirgod]

That's Very Strange. I've been having the Breaker trip alot lately myself here in my house, and the Electrician can find nothing Wrong.

Yesterday, I tried one of those New Microwavable Pig Skin Things (Like PopCorn), set the Microwave for 2 minutes, and the Bag caught on Fire.

Of course I followed the Directions on the bag, But It has been a very odd week endeed with appliences. Hec out of nowhere My DVD Drive decided to become the C: drive last Saturday. Virus, Spyware, and Zone alarm detected nothing.

Stephen looking over his shoulder.

[Iceman]

Pretty sure the catching fire things means that the metal surroundings in the microwave have been chipped somewhere, exposing the metal. Either that or its time for a new microwave.


On a side note, this happened last week at work (restaurant)

A waitress comes in and asks me to make a brownie sunday for a customer (regular occurance). So I take the brownie out of the fridge and toss it in a ceramic bowl in the microwave, again normal.  About 15 seconds goes by, I'm doing something else in the 45 seconds I had and all of a sudden theres a loud POP POP in the kitchen. Everyone just kinda stopped and looked at each other. Since nothing else happened, we just kept working.  I take the brownie out, and theres a dammed scorch mark on it.  Apparently, a piece of tin foil (that we used to cover the pan, never in direct contact with said brownie) had fallen into the brownies while they were cooling. 

Freaky.

[Nemesis]

Alrighty, turns out to be a poltergeist. Reply from GE tech support says I should have waited 30 minutes unplugged to "clear out the memory". Sure enough, after a whole day unplugged it know seems to be working again (plugged in that is).

OK you electronic techs, just what how in the hell does a Microwave keep "bad memory" for ten minutes?

Capacitance. 

The circuit can hold some power and it takes time to "leak" away. 

TVs can be really shocking to work on if you don't allow sufficient time for the stored power to leak away after unplugging them. 

If you ever had to clear your BIOS you likely had to unplug the computer, remove the battery and then short out 2 pins to drain residual power.   The same principle is involved.

[NJAntman]

Thanks for that explanation to that solution which apparently worked.

But if I might ask, just what the heck caused the problem? Can something as simple a say a build-up of static charge cause the circuit board inside to continuously engage in a repetitive cycle. Normally I have to physically push the buttons to have the microwave start. I know that there are no longer physical mechanisms (pulleys/chains/levers/et..) connected with on/off buttons, but what is it about circuits that can lead to this poltergeist-like behaviour? I'm just getting tired of hearing unplug or re-boot to fix the bizare behaviour of electronics. My inquiring mind needs a clue.

[Nemesis]

Thanks for that explanation to that solution which apparently worked.

But if I might ask, just what the heck caused the problem? Can something as simple a say a build-up of static charge cause the circuit board inside to continuously engage in a repetitive cycle. Normally I have to physically push the buttons to have the microwave start. I know that there are no longer physical mechanisms (pulleys/chains/levers/et..) connected with on/off buttons, but what is it about circuits that can lead to this poltergeist-like behaviour? I'm just getting tired of hearing unplug or re-boot to fix the bizare behaviour of electronics. My inquiring mind needs a clue.

My best guess is that an "electrical event" occurred.  Such an event could be a brown out, power surge or as you say a static discharge.  Such an "event" can cause transistors in the system to randomly change state.  In a PC that could result in a system crash.  In other electronic devices it can result in erratic behaviour, like your microwave.

Here is a silly appliance story (and true).  A friends parents had the refrigerator motor go bad.  I told him why, he called me an idiot.  The new motor went again in days.  The repairman told them to remove the refrigerator magnets (the entire door and one side were covered almost solid with them).  Each time they opened or closed the door those magnets were causing power surges and frying the motors.  Just as I told him.  They removed the magnets and the refrigerator gave them no more troubles.

[NJAntman]

Here is a silly appliance story (and true).  A friends parents had the refrigerator motor go bad.  I told him why, he called me an idiot.  The new motor went again in days.  The repairman told them to remove the refrigerator magnets (the entire door and one side were covered almost solid with them).  Each time they opened or closed the door those magnets were causing power surges and frying the motors.  Just as I told him.  They removed the magnets and the refrigerator gave them no more troubles.

Uh oh. Sounds like my wifes picture collection on our fridge!