Need appliance parts? Call 877-803-7957 now or use the parts search box:

Parts Search

Learn appliance repair at online the Master Samurai Tech Academy.  Learn more.  Earn more.

FAQs | Repair Videos | Academy | Newsletter | Podcast | Contact

  • Announcements

    • Samurai Appliance Repair Man

      ***READ THIS PRIOR TO STARTING A NEW TOPIC***   05/02/2016

      Topics with the complete and accurate model number in the topic title will get priority attention. You can validate your model number by entering into the form on this page: http://www.repairclinic.com/?clearLs=true For more help on using Appliantology effectively, please see this page:  
wapitiscat88

Samsung RF263 defrost sensor reposition

15 posts in this topic

Well, the evaporator is iced up again. I'm beginning to think that the drain may be clogging with ice and have read about repositioning the sensor to a different location on the evaporator. In one post the "last run on the suction side" was referenced for a different model. Can someone describe a similar location for the sensor on this model? Also, what are the tests to do at the evap assembly level with respect to the heater and sensor? Do I test these with power on? Do I test these while the unit is in forced defrost? Thanks.

 

Todd

Share this post


Link to post
Share on other sites

Need appliance parts? Call 877-803-7957 now!

Does the Defrost Heater work at all ?

what's the frost pattern look like of the Evaporator Coils ?

post pictures ..

Share this post


Link to post
Share on other sites

The coils are encased in solid ice. I'll take some pics when I pull the cover off. Also, I'll check the heater. Is this a simple continuity check or am I looking for certain resistance (or voltage) numbers? I have read the post regarding the replacement of the heater w/o swapping out the entire coil assembly.

 

Todd

Share this post


Link to post
Share on other sites

repositioning the sensor to a different location on the evaporator. In one post the "last run on the suction side" was referenced for a different model. Can someone describe a similar location for the sensor on this model? 

 

 

It's the same for this model.  Move the thermistor from the vertical tube to the last rung of the evaporator.  

 

Also, what are the tests to do at the evap assembly level with respect to the heater and sensor? Do I test these with power on? Do I test these while the unit is in forced defrost? 

 

 

Normally, you'd test the defrost system from the Muthaboard using the Fast track manual:  http://appliantology.org/files/file/52-samsung-fridge-rf266ae-rf263-fast-track-troubleshooting-manual/

 

But since you're going to be tearing apart the freezer anyway, you can test the resistance of the defrost heater and limiter at the wire harness inside the freezer.  

 

If the heater and limiter are closed (or something low resistance, see the Fast track), then you should still do a manual defrost test from the muthaboard and check to see if the muthaboard is sending 120vac to the defrost components.  

Share this post


Link to post
Share on other sites

 

 

 

If the heater and limiter are closed (or something low resistance, see the Fast track), then you should still do a manual defrost test from the muthaboard and check to see if the muthaboard is sending 120vac to the defrost components.  

 

 

So check for 120 VAC across CN70#5 and CN71#9 while in manual defrost mode. Amiright?

Share this post


Link to post
Share on other sites

That'll do it.  

Share this post


Link to post
Share on other sites

I got behind the unit tonight. Set the beast to manual refrigerator defrost and then crawled behind and opened the PCB panel. Checked voltage across CN70(white) and CN71(red) and got 120 VAC. Unplugged the unit and measured resistance across those same two pins and got 102 ohms. Tried to measure resistance of sensor but the CN's and the labeled wires were different from any diagram I had. Ending up trying to measure across CN30(purple) and CN76(gray) and got a goose egg. The probes on my multimeter are sort of blunt so I don't know if I was making good contact or not. Given that I'm not even sure that I was on the right pins I don't know if I can call this a sensor diagnostic or not. I figure I can check the sensor resistance from the "other end" when I open the evap coil cover and thaw it out. I thought that if I could diagnose anything as bad beforehand I'd wait and order the parts and have them on hand when I went in for the defrost. I'll have to coordinate with Mrs. Wapitiscat88 and see when I can open it up for the thaw out. Thanks for the help so far.

 

Todd

Share this post


Link to post
Share on other sites

Tore into the fridge last night to expose the evap coil. You can see the ice on the coils in the picture. Ice was also around the fan and down into the channels in the Styrofoam "ducts". After melting/removing the ice, I tried to check the resistance of the sensor on the coil but couldn't get a reading. I also checked the sensor associated with the fan and got the same result. Either I am totally incompetent at using my multimeter or there's some trick to assessing these sensors (or both). The ambient temp was around 80 deg. F Are these sensors "open" at that temp? I would figure they would have a variable resistance that moved with the temp. Anyway, I hooked up the fan and its sensor, put the unit into forced defrost and the heating element did heat up. So, still some mystery here. I suppose the less elegant route would be to blindly swap out the sensor when/if I have to melt the evap coil again. I suppose with a little more digging I could find a main board diagram that gave me a better idea of witch plugs and pins to use for testing the sensor. Anyone have any other ideas?

 

Todd

post-84651-0-68428600-1374240958_thumb.j

post-84651-0-96539200-1374240971_thumb.j

Share this post


Link to post
Share on other sites

now need to see a picture of the frost pattern at some time "between" those (2) pictures.

After the frost is melted, let the Compressor run an hour or two,

then take another picture

Share this post


Link to post
Share on other sites

What is this? Some sort of apprenticeship hazing ritual?  :wink:

 

Are you thinking it's a refrigerant issue? I'll try this the next time the refrigerator is nearer to empty. Mrs. Wapitiscat88 will have it filled after today's trip to the grocery. So the steps would be ... empty fridge, remove cover, melt ice/frost, replace cover, run for 2 hours, remove cover and document frost pattern. Sound about right?

 

Todd

Share this post


Link to post
Share on other sites

yes

yes

yes

Share this post


Link to post
Share on other sites

Looks like you have not moved the sensor yet. I think you meter lead might not be getting contact with sensor wires, I doubt both sensors are open, that should also cause error codes.

Share this post


Link to post
Share on other sites

Yeah, I wasn't real confident about moving the sensor. In an earlier post, I was instructed to move it to the last rung of the evaporator. Is that the last horizontal rung before the vertical turn? I'll upgrade my meter prior to the next go round and see if I can get better diagnostics.

Share this post


Link to post
Share on other sites

Could be an air flow issue.  Provided the air channels in the evaporator cover are clear (I usually run hot water through to be sure), check the evaporator fan motor operation.  Should be able to hear the fan running a couple of seconds after closing doors.

Share this post


Link to post
Share on other sites

The refrigerate enters the evaporator coils thru that tiny tube called the capillary tube. This tube is so small it restricts/meters the refrigerant so that it flows at the proper rate. The refrigerant exits the evaporator thru the larger copper tubing, put the sensor there

Share this post


Link to post
Share on other sites