NS-RTM12SS7-C Need help identifying Insignia fridge GE-built?

Cubytus

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Hi there,

I need to repair an Insignia fridge that defrosts a bit too aggressively. Even with only light frost on the evaporator (technically no need for defrost), auto-defrost turns on. While the freezer is normally around -10º, during defrost it shoots past +7º, way too high, spoiling frozen food in the process.

Insignia is Best Buy's home brand, and BB doesn't sell officially sells spare parts. However, the fridge appears to use GE / Haier / Midea parts, and is superficially similar to models GPE12FGKWW or WHD-423FW1.
View attachment 43186
The controller housing appears on some GE compact fridge models. Controller is sealed inside a secondary enclosure that doesn't have any marking on the outside.

Problem is, I can't find any parts for these alternative models, either.

Can anyone help me identify this fridge?
Also, what would be the most likely culprit with the malfunctioning defrost?
 

Jake

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Hi,

You photo didn't come through, please upload it again.:)

Jake
 

Jake

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Yes, I see now.

I can't locate any tech. data information or parts for this model either. I don't know what to tell you, unless you go back to Best Buy and see if they can find anything on it parts wise.

Jake
 

Jake

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I don't know, I will ask the other techs if they do know.

Jake
 

Dan O.

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By Midea?

Some Insignia major appliance models are made by Mabe (GE Mexico/Canada). That one however looks like it’s made by Midea. A simple Google search turned up this:

LINK > https://encompass.com/model/ISGNSRTM12SS7C

It lists this:

17131000000175 Insignia Main Control Pcb
17431000001412 Sensor (Defrost)





Dan O.
 
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Jake

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Thanks Dan for assisting Cubytus on this!

Jake
 

Cubytus

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Thanks Dan, much appreciated!

I had a look on the Insignia NS-RTM12SS7-C, the parts all say "not available", but cross-checking part
17131000000175 Insignia Main Control Pcb, it also fits Midea NS-RTM12SS7CREF, and part seem available. Go figure.

Still, the control board is naked on Encompass' website. Mine sits in a small enclosure (see picture). If I were to replace the board, I guess I'd have to crack it open?

Now, what would be the most likely culprit with this fridge "overdefrosting"?
 

Dan O.

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Alt suppliers

the parts all say "not available",
I've not used them myself and don't know how their site functions (apparently not well?). I did a Google search for the part number and found a number of suppliers that listed that part for sale.

Mine sits in a small enclosure (see picture). If I were to replace the board, I guess I'd have to crack it open?
Some of the parts sellers listed on Google showed it in the housing.

Now, what would be the most likely culprit with this fridge "overdefrosting"?
I'm afraid I have no idea, I've never worked on a Midea model nor seen a service manual. I'd guess either the control or the defrost sensor might be suspect? That's just a guess though.

Dan O.
 
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Cubytus

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True, I haven't seen any service manual for these cheap, underpowered fridges. I guess repairing a faulty one isn't worth the cost of a qualified technician.

On the other hand, these cheap fridges don't have that many parts, except the "black box" that is a proprietary, microcontroller-based control board, so there's not so much that can go wrong. But no modern fridge uses mechanical timers and thermostats anymore.

I did find a picture of part 17131000000175:
43584


They pictured the board with the enclosure cracked open. I guess It's not as hard to open as I would imagine.

So, your educated guess would point toward the control board or the defrost / freezer sensor?
 

Dan O.

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Defrost termination?

If the fridge isn't shutting the defrost off soon enough as you suggested, I don't see any other component that could cause it but I do not know how that defrost system is designed to function. The defrost sensor just being mislocated might cause it too?

Dan O.
 

Cubytus

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Bad news... The control board is back-ordered for the next 4 months at Encompass :(
I thought about using a generic STC-9100 controller, though it's still unclear how defrost must be programmed.

Where is the optimal location for the defrost sensor, anyway? I found it hanging in the air on the right side of the evaporator, behind the defrost fuse.
 
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Dan O.

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Dan O. previously said:
I did a Google search for the part number and found a number of suppliers that listed that part for sale.

Dan O. previously said:
I'm afraid I have no idea, I've never worked on a Midea model nor seen a service manual.
Maybe someone else has had some experience with that offshore manufacturer to answer your question?
 

rickgburton

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Best Buys wants to do the same thing Sears did. Best Buys Insignia is like Sears Kenmore. That means Insignia can be made by anybody. Their 3 biggest contributors are LG, Samsung, and China. Most Insignia refrigerators are rebranded previous models of LG and Samsung.
Cubytus said:
While the freezer is normally around -10º, during defrost it shoots past +7º, way too high, spoiling frozen food in the process.
+7°F is still 25° below freezing. The defrost cycle is a short cycle, maybe 20-25 minutes so a 17° increase in temperature from -10°F for 20 minutes will have no effect on frozen food. To get an idea of what I mean, take a one pound package of hamburger out of your freezer and set it on counter for 20 minutes. That's an 80° increase in temperature. After 20 minutes you'll have condensation on the outside of the package but the contents will still be frozen. The defrost cycle is controlled one of two ways, adaptive or timed. If it's adaptive the control board uses sensors or thermistors and keeps track of compressor run time, door openings, and the length of time of the last defrost cycle. If it's timed, most manufactures will use a defrost timer but it's not uncommon to find a timed defrost cycle controlled by the board. Many people mistakenly think the defrost thermostat controls the length of the defrost cycle. The defrost thermostat is a safety device. It's mounted to one of the evaporator coils, usually the last coil before it exits the freezer. The reason is the evaporator temperature is much colder than the freezer temperature. Some evaporators temps can be as low as -30° to -40° this keeps the defrost thermostat from opening prematurely during the defrost cycle.

If food is spoiling it's not due to a defrost cycle as long as the defrost thermostat and defrost heater are working correctly. I suspect the problem is with the sealed system. Here's a simple test you can do. Compressors normally run warm to very warm. A compressor that runs hot to extremely hot usually indicates a system issue. The defrost cycle has no effect on the compressor temperature. Feel the compressor with your hand and see if it's warm or hot.
 

JAYCANADA

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I've been having the same issue with my fridge of the same model.

Initially when my tenant tried to increase the temperature to the highest setting it would always reset itself to the medium setting.

I have noticed when I disconnect and reconnect power that the led lights on the the controller housing go through a certain sequence...
All 5 LEDS flashing then settling with LED #1 and LED #3 staying on.

Do any of you professionals know where I may be able to find information regarding these error codes?

Is there a way that I can determine who manufactured this particular fridge?

Thanks all.
 

Dan O.

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JAYCANADA said:
Is there a way that I can determine who manufactured this particular fridge?
Dan O. previously said:
That one however looks like it’s made by Midea.

Do any of you professionals know where I may be able to find information regarding these error codes?
I do not. I've never had any dealings with Midea and when I contacted insignia.com about one product they had absolutely no information on it. You can try for this specific product though.

Dan O.
 

rickgburton

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Every new appliance regardless of of manufacturer comes with a tech sheet and wiring diagram. Trying to find its location can be a bit of a task. Common locations for the tech sheet is; behind a toe grill, under a hinge cover, inside a control panel. Glued to the back of the machine or taped to the bottom or sides in the condensor compartment behind the bottom grill. You might not have the tech sheet if you purchased the machine used or if there was any previous service done on the machine. The tech sheet will have all the error code information.
 

Cubytus

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(…) That means Insignia can be made by anybody. Their 3 biggest contributors are LG, Samsung, and China. Most Insignia refrigerators are rebranded previous models of LG and Samsung.
That would explain why the same part number can be found under different brands, including GE and Midea.

+7°F (…)
Except that these weren't ºF, but ºC. I should have specified. +7ºC is above safe temperature for a fridge, let alone a freezer.

(...) this keeps the defrost thermostat from opening prematurely during the defrost cycle.
I read somewhere these thermostats only act to prevent catastrophic failure (read: fire) should the powerful heater not turn off in an enclosed space. What temperature do these safety thermostats open, anyway?

If food is spoiling it's not due to a defrost cycle as long as the defrost thermostat and defrost heater are working correctly. I suspect the problem is with the sealed system. Here's a simple test you can do. Compressors normally run warm to very warm. A compressor that runs hot to extremely hot usually indicates a system issue. The defrost cycle has no effect on the compressor temperature. Feel the compressor with your hand and see if it's warm or hot.
I knew I missed something: I should have thought of testing the actual defrost themostat to check if it has been opened by the too-high temperature in the freezer. Thanks for the tip! I may have additional information once I receive the USB temperature logger later this month.

The compressor on this model runs very hot, for very long periods of time; the condenser also runs pretty warm, but I suspect it has too small a capacity for the volume. GE and Danby actually say somewhere in their manual that it's normal for an "energy-efficient fridge" to be running 80%+ of the time. In a 22-25º kitchen, no seal leaking nor still-warm food inside. I'm no expert, but that sounds BS to me.

(For the record, I "hand checked" another fridge where the compressor was running boiling hot, but the condenser was barely warm, while both freezer and fridge were warm - just pushing heat from the compressor itself?. Best guess: compressor wasn't compressing anything anymore, fluid had leaked, or decompression valve had failed.)

All 5 LEDS flashing then settling with LED #1 and LED #3 staying on.
This code is in the table on top of user manual, page 19. It means the defrost sensor is either bad, dead, or disconnected.

Wiring diagam for Insignia NS-RTM12SS7-C:
43673
 

rickgburton

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°C and not °F makes a difference...lol Looks like you don't have a defrost thermostat only a fuse. It works the same way except it's a one shot deal. The thermistors send information to the control board and the board uses that information along with compressor run time, door openings, and length of time the heater was on during the last defrost cycle then decides when to start a defrost cycle. The defrost thermistor is used to terminate the defrost cycle.
 
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