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Jason, Home Appliance Tech
Category: Appliance
Satisfied Customers: 798
Experience:  15yrs experience
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My Samsung MO# XXXXX 253 BABB frig wont go into defrost. How

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My Samsung MO# XXXXX 253 BABB frig wont go into defrost. How do i fix it?

Thank you for using Just Answer. I will be glad to assist you in your answer. Think about safety when doing repairs, electric, water, gas, ect.


Please look in the fridge section and give me the BOM, or MODEL# XXXXX the data sticker on the inside side wall please.....thank you

Customer: replied 4 years ago.


Customer: replied 4 years ago.


Please verify if the fan is working on the fridge section. I have seen where this fan is not running, causing it to look like the unit is not defrosting in the fridge section. You may have to close the door, and pull back the door gasket and listen for the fan. Some of these models only run with the door closed....Thanks
Customer: replied 4 years ago.

i just hold the door switches closed - frig and freezer fans (respectivley) come on after a few seconds



Ok, which side is not defrosting, fridge or freezer?
Customer: replied 4 years ago.

freezer _ -- i've been tracking temps - Frig high start in mid 30's now in mid 40's soon to be mid 50's - FREEZER temps never rise above freezing w/ probe in bottom Freezer wall vent (near) evaporator . lows consistent at neg6

Customer: replied 4 years ago.

how do i invoke defrost?

Ok, you will need to remove the inside rear cover of the freezer, defrost the cooling coil with a hair dryer, careful not to melt the liner. Replace the 2 sensors on the cooling coil, #'s 12 and 13 on the following parts website. If this information has assisted you, please give a good to great rating. Thank you


Customer: replied 4 years ago.

are those thermisters? can i test for ohms? Plus ... without invoke defrost to see if this thing heat... how do you know it's not

Drain Heater, Freezer

by Samsung
Part Number AP4139332


(not trying to be disagreeable - i've just changed part on advised from Just Answer that didn't need changed)

PS ... i've got access to all kinds of pretty colored wires at the top freezer hing on their way to the Ctrl Board

You can ohm out #12, it is the defrost thermostat, it works like the normal bi-metal t-stats. The other is a thermistor. I do not see a heater for this coil on the diagram, so it may be built into the coil itself. Look for a wire harness coming out of the top of the coil if there is one. If all that test ok, then the main board would be the issue. Most of the time I replace the 2 sensors for a good repair. Thanks again

Customer: replied 4 years ago.

you know where samsung usually stashes their wiring Daig on these frigs? I should be able to ohms these parts out from the wire harness .. right?

Customer: replied 4 years ago.

i'm getting 12.9k on the thermistor @ abour 40degrees .... i was suprised to find the evap NOT iced up. i guess my probe's not picking up the integrated heater. how about a bad thermistor on the frig side ? would that explain the 20degree temp creep in the frig?

The thermistor reads good. I thought you had trouble with the freezer, not the fridge. Maybe I need to backtrack here. What exactly is going one with this unit. Do you see frosting? You said fans work. I know there is a temp issue. You originally said fridge was not defrosting. I asked again, which we started to say that the freezer was not defrosting. Your last post said that the fridge has a temp issue. Both side has its own cooling coil. So one side should have a cooling problem where the other does not, unless there is a Freon issue. Please clarify what is going on, because we seem to be bouncing back and forth here. I am here to help, please bare with me, just trying to clarify the issue here....Thanks

Customer: replied 4 years ago.

i'm back! sorry , i shouldn't make asumptions on this samsung, Aside from the freezer not icing up it was acting like a typical frig ice blockage/lockup ... the Freezer is fine (didn't know it had 2 evaporators)


The Frig high temps start in mid 30's now in mid 40's soon to be mid 50's

over the coarse of 4 weeks


So the fridge evaporator is freezing up, did I understand you correctly?
Customer: replied 4 years ago.

yes ... just took it apart ,, it is frozen up

testing parts now .... still can't find the schematic ...

Customer: replied 4 years ago.

yes ... frozen up ..... AP4136145 seems to be permanantly closed .... full continuity @ 80degrees



what wires can i ohm to test the heater? or energize to start defrosting?

If both sensors have a reading, test the heater. If you look at the top of the cooling coil, the front loops. Follow them to the top and you should see some wire coming out of the loop. The front facial loops of this cooling coil is the electric heater circuit. You will need to see if those wire have continuity unplugged. Please let me know what you find.....Thanks
Customer: replied 4 years ago.

no continuity on the evap/heater coil /// thanks

You bet. Order the whole coil. You can bend tabs and replace heater only instead of the whole thing....just a FYI....please do not forget to give a good to great rating for answering your question.....thanks again.
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