Frank from Deeeetroit wrote:
"terry" wrote in message
oups.com...

On Jan 28, 2:12 pm, "Frank from Deeeetroit"
wrote:
I have a 4 year old GE side by side refrigerator. The evaporator coils
freeze-up about once a month. We have to un-plug the 'fridge and let the
coils thaw out for the unit to run properly.

One other symptom, one of the two light bulbs (the upper one) in the
refrigerator side of the unit will not work. A new bulb will not work,
the
switch is good, the second bulb works.

I have a basic understanding of the system. I thawed out the coils two
days
ago and vacuumed out the area under the 'fridge, behind the bottom grill.
Where do I start the troubleshooting?

If understand correctly the coils in the freezer side ice up?

That is correct.

Maybe the automatic defrost circuit is not working? It usually
comprises a timer switch, and heaters that thaw out the ice so it runs
away through a drain.

I suspect that is the problem, but what part is brokern in the system.

Many years ago our defrost timer stopped working (the little clock
motor that ran it went open); cos otherwise i might have been able to
repair the timer switch.
It took Sears and myself a couple of weeks to bring in a replacement
and myself to install it. In meantime we wired a temporary manual
switch in place of the timer. Had to remember to not leave it in the
defrost mode before going to bed!
It's worked now for at least 15 or more years.


The way I undestand the system, there is a mother board that controls
everything, a defrost timer, and the defrost heating element. Just
wondering where to start testing first with my volt/ohm meter.

thanx

Frank
It's tough when they use fancy
electronic (microprocessors or pic chips)
to control a simple function. One other
thing, there might be a temperature
senor to turn off the defrost heater
element once the coil temperature reaches
thaw. This is probably to conserve
energy and not put extra heat into
the freezer, only to have to run the
compressor to take it out later. With a
simple meter you should be able to check
out the heater resistance. I should
be rather low, like under a few hundred
ohms or even much lower.
The temperature sensor, if there is one,
could be open or closed depending
on the design and the temperature at the
time of reading. A schematic would
be of tremendous help. Check the back
inside of the unit, behind the panel,
etc. Or, search for it on the internet.