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Forum Index => Refrigerator & Freezer Repair => Topic started by: madbchron on December 31, 2009, 10:05:18 AM

Title: iced over evaporator
Post by: madbchron on December 31, 2009, 10:05:18 AM
I noticed water from under the freezer door on the floor
and thought i had the same problem which you previously helpe me with I checked the evaporator drain and it was clean and the pan was empty. so i remover the evaporator cover and it was a solid block of ice i then turned off  the compressor and lef the door open for 3 hrs for it to defrost . by the way the water did drain well to the pan the water i was seeing on the floor was actually coming from inside the freezer door i put a pan to collect it and i would say that there must have been a least a quart + of water frozen  inside the door ? why
I checked your parts  list and i found the defrost heater and thermostat and also the adaptive defrost board which i assume are possible culprits how can i check out these two controls out to verify
which need to be replaced  just for your info after i defrosted the evaporator i replaced the cover  and let it run for about 12 hrs I again removed the cover to inspect and found only a very light film of of frost an th lower side of the evaporator and it seemed to be running normal but i think i should check out the defrost system or any other things that you would recommend
Thanks madbchron

Model msd2756geq

Title: Re: iced over evaporator
Post by: JWWebster on December 31, 2009, 10:23:45 AM
It takes a while for a defrost problem to develop. I would check the heater for continuity. If that was open I would of course replace it and I would automatically replace the defrost thermostat. Because that is always recommended. If the heater was good I would check the defrost thermostat. these are tricky, they need to be at a temp of 25f to have continuity. So ya gots ta be quick or it will warm up and open. That is its job. It shuts that heater off. The dwell time(that's the time the ice box stays off before cooling cycle begins is anywhere from 20 to 45 minutes and if that heater stayed on that long it would not be pretty.If it turns out both them things are ok then I would get the adc out and clean up the connections, it is sitting in a damp ice box next to the cold control and light in the fresh food compartment so plenty of oppourtunity for corrosion to show its ugly head. People are so fast to buy parts these days without checking the simple stuff.
Title: Re: iced over evaporator
Post by: jumptrout51 on December 31, 2009, 04:56:49 PM
You can turn your cold control on then off 3 times in 6 seconds to activate the defrost control. If you have a clamp on amp meter on the incoming power supply wire at the rear of the fridge you should read about 4 amps. If you do all is OK.
If the fridge shuts off and you read no amps,replace the defrost thermostat for sure,the calrod heater can be checked with your meter for continuity. If open,replace it too.
If it does not turn off,replace the ADC(defrost board).
Title: Re: iced over evaporator
Post by: JWWebster on December 31, 2009, 05:59:40 PM
Let me get this straight: *Turn your cold control on then off 3 times in 6 seconds to activate the defrost control.Using  a clamp on amp meter on the incoming power supply wire you should read about 4 amps. If you do all is OK. If the fridge shuts off and you read no amps,replace the defrost thermostat for sure, then the defrost heater must be checked with your meter for continuity. If open, replace it.
If the ice box does not turn off for the test*, Then replace the ADC (defrost board). Right?
Title: Re: iced over evaporator
Post by: jumptrout51 on December 31, 2009, 06:05:23 PM
Yep. Well actually it should have read turn the cold control OFF then on 3 times within 6 seconds. The fridge has to be on and cold for this to work.
Title: Re: iced over evaporator
Post by: JWWebster on December 31, 2009, 06:25:29 PM
Excellent
Title: Re: iced over evaporator
Post by: RAH52 on December 31, 2009, 09:09:58 PM
If my memory serves me right the thermostat and heater come together
Title: Re: iced over evaporator
Post by: AJ on December 31, 2009, 09:20:27 PM
If my memory serves me right the thermostat and heater come together

That's correct, they do come together.

Heater and thermostat: Part# 61006199icon
Adaptive Defrost Board: Part# 61005988icon
Title: Re: iced over evaporator
Post by: magician59 on February 19, 2010, 01:00:26 PM
If you'll allow me to piggy-back on this thread: If you want to force a defrost, on some of the ADC boards can be forced by shorting between the left two terminals with a flat bladed screwdriver.
Title: Re: iced over evaporator
Post by: JWWebster on February 19, 2010, 01:05:53 PM
You unplug the ADC and jumper the left 2 quick connect terminals with a screwdriver?
Title: Re: iced over evaporator
Post by: magician59 on February 19, 2010, 01:26:29 PM
Leave it plugged in. If it immediately goes into defrost, the board is good.
Title: Re: iced over evaporator
Post by: JWWebster on February 19, 2010, 03:47:08 PM
what happens if you short out the wrong 2?
Title: Re: iced over evaporator
Post by: magician59 on February 19, 2010, 04:07:56 PM
I don't recall ever having done that; I'll have to get back to you as soon as I locate my notes.
Title: Re: iced over evaporator
Post by: schaffersapplian on February 19, 2010, 04:50:44 PM
Testing the Maytag ADC. SxS or WxS only

-The unit must be running (if not the ADC will cycle though the test mode in 2 seconds)
-Disconnect plug from wall
-Remove & drop component housing
-Connect amp meter to yellow
-Reconnect plug
-Apply screwdriver between L1 ands test point for 3 to 4 seconds. Then remove and hear a relay click
-23 minute Defrost Cycle initiates
-Compressor and fans turn off
-Amp draw is approx. 4.5 or 500-600 watts
-disconnect plug
-Perform resistance checks
-Reconnect plug to reactivate Run cycle
Title: Re: iced over evaporator
Post by: RAH52 on February 19, 2010, 08:08:37 PM
Something I've noticed lately .You determine the ADC is bad and replace it .You button the fridge back up,plug it in and nothing happens ,only interior light i.e no compressor start up . You start to sweat and second guess "did I knock a wire off ,whats going on " ? Have patience the fridge will start all by itself in about 5 minutes and work fine .Why it takes so long to restart is beyond me . I'm thinking the new ADC have some sort of a delay built in like the old whirlpool system 2000 fridges had .Remember those.... if you unplugged them and plugged them back in they took 7 minutes to start up . 
Title: Re: iced over evaporator
Post by: JWWebster on February 19, 2010, 08:24:32 PM
Cool