Samsung RSG257AARS

[Arsenal101]

Hey Everyone, 

Need a little help diagnosing my Samsung french door fridge/freezer. The freezer side seems to have a very hard time cooling down to the temperature I set it to. The fridge on the other hand is fine. All of the cooling/circulation fans work as they are supposed to. When I pulled the back panels off to expose the evaporator coils I noticed that the freezer side was frosted right up on the top of the coils but not so much on the bottom. IN my research it looks like that could be a restriction to the flow of refrigerant. Then I learned that there is a thing called a 3 way step motor valve. Which diverts the flow of refrigerant to either the fridge or freezer. and if that gets stuck on the freezer only cool mode, the fridge wont cool, if it gets stuck on both fridge freezer mode then it will still work.. just with more energy. What I believe is happening is that it is stuck on the fridge only cooling mode  as the freezer seems to be getting very little flow of coolant. 

I found a tech trouble shooting tip here Samsung troubleshooting It super little information on troubleshooting the step motor valve other than to test the resistance between the common and the 4 phases of the motor, all of the phases should be 40 ohms + or - 10%. I have verified that the windings are all good. from what I can tell it seems as though the portion of the valve that actually move back and forth is stuck... it does not seem like there is a way to move it by hand? or how could i trick it to move? 

Does anyone know how to check the "signal" to the valve? All I see on the wire diagram is a 13v common and 4 phases... but that doesnt tell me which direction its moving, what setting its in etc...

 

Sorry for the longggg right up. I would super appreciate any info anyone has on this topic

[johntech]

If you unplug the unit and plug it back in a few minutes later the valve will move to the home position and if you have your hand on it then you will feel it move. If you have any frost on the evaporator then you know the evaporator is getting refrigerant. The evaporator in the freezer is bigger then the refrigerator evaporator so it takes more refrigerant for the freezer evaporator to operate . Sounds to me like you may have a refrigerant leak.

[Arsenal101]

Thanks Johntech, Do you know what position is "home"? IE, Freezer/Fridge or both?  Is there a port I could test pressure on? I have automotive AC guages if they use the same style ports but I was unable to find any. 

I should also add that it seems like if you put the fridge into power cool mode it seems like it overrides the freezer power cool mode. And even with the freezer in power cool mode it took forever to cool down to -14... like 10 Hours to cool down. 

I will try to see of the valve moves by unplugging it and plugging it back in. 

[johntech]

Home position is both freezer and refrigerator are open. Power cool can work on both at the same time. All it does is bypass the set temps for a little while allowing it to get colder. If you are low on refrigerant then it would be obvious when both evaporators are running by a partial frost pattern on the larger evaporator.  You can check refrigerant levels but you would need to add a valve and remove it after service. Automotive gauges are not the right gauges. If you do not know what you are doing you could contaminate the sealed system and ruin the refrigerator. You are supposed to be epa certified to get into the sealed system or buy refrigerant. If you are low on refrigerant and it was working before that would mean you have a leak. Most cases that means it's time to start shopping for a new refrigerator.

[johntech]

Did you check that the condensor coils are clean? That can cause similar conditions. 

[Arsenal101]

I will check the condenser coils when I get home. I just bought the fridge for super cheap in the hopes that I could fix it. It was sold thinking the evaporator fans were not spinning. When I got it home I got them to spin no troubles. 

That's interesting that there is no valves or ports on the sealed system. How would they be able to charge the system? I was looking at the fast track tech sheet and says it takes 7.1 oz of r134a refrigeratant which is the same as regular automotive refrigeratant. 

Condenser coils are a real possibility. They looked pretty grungy when I looked in towards the bottom from the back side. That would be pretty sweet if that's all it was. 

When I first opened the motherboard compartment it smelled like burnt electrictronics but I couldn't find any charred marks. And it seems to be working alright as far as all the sensors. 

I'll update when I get home and check the condenser coils.

[Arsenal101]

Double check the condenser coils and they had some dust on them but they weren't straight up plugged. I vacuumed them off anyways just be sure. 

Interesting quirk though. I put the fridge into power freeze mode which is supposed to just cool down as much as possible without any reguards to temperature, while in power freeze mode the free evaporator coil didn't even frost up... I am suspecting the motherboard just because its doing weird things... 

any thoughts?

[johntech]

They don't put service ports on refrigerators because it is a potential leak spot and you have to be liscensed to open the sealed system and they don't want unqualified people contaminating the environment. There are laws about putting refrigerant in leaking systems.  Normal operation of the unit is 20 minutes freezer cooling then 20 minutes refrigerator cooling till set point temps are reached. Then the control will cool sections as needed. The valve does not stay in the home position it just does self checks on start up. When I said you can power cool both sides at the same time I ment it would bypass the set point for example the freezer will cool to -13 degrees for x amount of time. Then when that is met it will cool the refrigerator. But if the set temps are not met it will go back and fourth 20 min freezer then 20 minutes refrigerator. Nothing that you posted makes me think you have a board issue. Everything is pointing to sealed system failure. That's prob why you got it so cheap because they new it would cost as much as a new refrigerator to repair.

[johntech]

Basically if the condensor coils are clean, all the fans are running, the compressor is running and you have a partial frost pattern on the evaporator then you have a sealed system problem and it's time to start shopping.

[Arsenal101]

So far it has been an hour since I unplugged and warmed up the interior of the fridge... both fridge and freezer were 65ish degrees. I plugged it back in and the fridge side started to cool immediately and is now down to temp... the freezer is still 63 degrees and there barely any frost on the evaporator coil. plus the fan was not even running. That's what makes me think its a board thing... its like its not even trying to cool the freezer. I don't think its a refrigerant thing because even before this I had it down to the set temp. and there was more frost on the evaporator than there is now. 

[BrewHobbyTech]

2 hours ago, johntech said:

Normal operation of the unit is 20 minutes freezer cooling then 20 minutes refrigerator cooling till set point temps are reached. Then the control will cool sections as needed.

I thought all the dual evaporator refrigerators with the three way valve ran the first 20 minutes for the ff evaporator and then 20 minutes for the freezer evaporator. I know that's what the LG models do. I've worked on a few Samsungs but don't remember, maybe they're the opposite. I'll have pay more attention on the next one I work on.  

[BrewHobbyTech]

Thinking it's a board problem is wishful thinking, unfortunately. I agree with johntech, it's definitely a sealed system problem. It's one of two things, either a leak or a restriction. From the info you have provided I'll go with a restriction. It's common, especially with these dual evaporator systems. My guess is the restriction is at or near the end of the cap tube that goes into the freezer evaporator. If they gave you enough cap tube to work with you can repair it with out replacing the cap tube, but they usually don't give you enough to work with and replacing the cap tube would be the only thing you can do. I've got some experience doing this.....drilling holes, using a grinder in back of the fridge, etc. If the cap tube doesn't have to be replaced I would charge around $300 or so, maybe more....and if the cap tube does need to be replaced I would charge around $400 or so. My prices are at the low end, so if you call a company out to do the job they will most likely quote you a higher price. 

[Arsenal101]

So if I'm understanding this correctly the capillary tubes are the tubes that go from 3 way valve to the evaporator coils. There's one bigger line from the compressor and the one much smaller capillary tube for each evaporator coil? And the inside diameter is so small that the the tiniest piece of debris could cause a clog. 

 

I should note that I popped the cover off the fridge side evaporator coil and noticed that it was not even frosted all the way from top to bottom. So if both evaporaters are not working 100% then that would indicate a leak or low on 134a refrigerant?

[Koi Guy]

If this were my call I would suspect refrigerant leak. I'd install a saddle process port and read my gauges. If in a vacuum I'd add some refrigerant to see if the pressure rises. If it does, I am pretty sure I have a leak, if the pressure is not rising I am pretty sure I have a restriction. If it has a leak I would add a UV dye and add refrigerant. I'd come back in a week or so and use my dye detection kit to see if I can find the leak.

I've changed out a dozen or so Samsung refrigerator evap coils. The manufacturer solder joint on the discharge side of the evap coil seems to be a problem spot. This is not a job for an inexperienced person. In my area I get about $650 for the complete repair.

[BrewHobbyTech]

1 hour ago, Arsenal101 said:

I should note that I popped the cover off the fridge side evaporator coil and noticed that it was not even frosted all the way from top to bottom. So if both evaporaters are not working 100% then that would indicate a leak or low on 134a refrigerant?

This last bit of info you provided would change my diagnosis and say you have a leak. And yes, the cap tubes are the small copper lines, and they do get clogged, either partial or total restriction. It's also possible, from some of your other info that you could have a restriction in your freezer evaporator coil, and have a leak. I just worked on an LG refrigerator last week that had that problem. Never seen it before but now I know the problem can and does occur. I doubt that it happens often but with these newer refrigerators.......who knows? It's definitely something to keep in mind because it can drive a tech to drink trying to figure out the problem.  

[Koi Guy]

I found a clogged filter dryer on a Samsung dual evap. Had clear cap lines. After seeing the filter dryer I replaced compressor as well and had no issues.

This is the worst filter dryer I've come across...

[BrewHobbyTech]

Wow, that's some nasty stuff Koi. Anyone know what is causing all the crap build-up in these newer refrigerators?? 

 

[Patio]

Hi all,

I have a Samsung side by side RSG257  AABP model and have a temp problem..Freezer LED temp reads freezer as being 0 Degrees F but actual temp inside using thermometer is only 28 degrees.

Could this be a bad sensor or?  (fridge side temp matches display spot on)..Thanks