Hi, my name is Mike and I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. The issue certainly sounds like ice buildup on the evaporator or fan. You would need to empty the freezer, remove back cover plate, then you see the motorized damper that spins around, make sure it free of ice, the stick on heater works, the magnetic sensor, damper and switch are all seated properly. Every time you turn the power on it should spin around a few times freely. Then stop closed if the fridge is cold, or stop half open if the fridge needs cooling. This can be caused by having items close to the internal vent causing the blower to freeze. It very likely could be fixed by moving any items away from the vents and if you find ice on the damper melt the ice with a hair dryer.
I'll have a look as you suggest
Very good. If something comes up I will be available if further questions arise. You can still ask questions even after rating my service if something else comes up. I will always respond although I am going to run out for an emergency plumbing call but still respond if something comes up as I will answer any questions you have .Mike
Damper was free of ice. It spun around a few times and stopped half open when I switched on. I can't tell what it would do if the freezer was cold enough. There was some ice on the evaporator which I've now removed, however I didn't think it was excessive. I can't tell if the stick on heater (you mean the one next to the damper?) is working but since there was no ice near it I assume that it is. The damper is seated correctly. As as far as I can tell so is the switch between the damper motor & paddle. Where is the magnetic switch that you mentioned? Brian
Correction: what I thought was the switch is the magnetic sensor. That is seated correctly. So, where do I find the switch? Brian
Additional: I've now checked the resistance of the stick-on heater and it was 8 kohm. Brian
So removing the ice from the evaporator did not solve the issue? Was the fan hitting any of the ice?
Sorry for the delayed response. I had to run out for a service call.
I've not reassembled it yet so I'll let you know. What was the switch that you mentioned? There was no ice near the fan - it was spinning freely and quietly. When the fridge/freezer was running there was air flowing so the fan must have been running OK then. Brian
The damper switch is what I was referring to but I am thinking that removing the ice was causing the issue. Usually the issues that involve what you have described is if items in the freezer deflect the cool air from coming in and ice forms on the evaporator.
There was nothing in the way of the vents so cold air was getting into the freezer compartment without restriction.
Ok. So now that the ice has been cleared is it working now?
I reassembled everything and set it running. It is behaving as before. It ran for 2+ hours but when I woke up and checked it it was not running and the temperatures I measured suggested it should have been. To confirm I left the fridge door open and it has still not come on even at 12 °C, even if I then shut the door. However, all I need to do is 'reboot' it by switching the power off and on and it starts running.
Leaving the door open will cause ice to form. The freezer will not work if you leave the door open.
I'm talking about a few minutes to prove that it isn't working properly. It didn't work when I then shut the door. But it did if I then rebooted it.
Oh ok sorry. Give me a couple minutes to review.
It has got to be the relay.Unplug the power. Follow the wires from the side of the compressor to find the metal terminal box connected to either side of the refrigerator compressor. Open the cover to access the relay switch. Inspect it for scorch marks. If you shake it and it rattles it is bad.
Thanks for that but it's late and I don't want to wake the Mrs. I'll try it in the morning.
Very good. I can't blame you for that. It is 11pm here. I will be online again in about 8 hours. Chat with you then...
Hi Mike, There was a plastic box on the side of the compressor and when I got it off it did say Cover Relay. I couldn't see how to remove anything further so I didn't. I can't see any scorch marks and no rattles although with it still attached it's difficult to do much shaking. I'm not sure what components are underneath. I came across a service manual for an LG model that had a diagram of an Over-Load Protector (OLP) that looks like the top part of what was under that cover. My model has a circuit diagram that shows a OLP. Could the bottom part be a Positive Temperature Coefficient (PTC) as in the LG rather than an old-fashioned relay? This is a device that energises the start winding on the compressor motor. Unfortunately the Samsung circuit diagram doesn't identify the component on my machine, but the contact numbers are virtually identical to those in the LG diagram.
I've also determined that, when the compressor should be on but isn't, the fan also isn't working. According to my circuit diagram, if the fault was in the relay/PTC / compressor / OLP area is shouldn't stop the fan from working. So, I suspect that the fault is elsewhere.
I am here. Wheels turning a little slow. Thinking.
I've got to go out for a few hours so I'll catch up on your response when I get back. Thanks. Brian
The sequence is the power on ,then liquid solenoid then low pressure switch then compressor starts freezing, then fans come on then timer activates defrost mode, liquid solenoid closes defrost for about 30 minutes or so then compressor back on. So with that being said it sounds like the heater may be working but possibly the defrost timer. Let's check that next. Remove the timer and check continuity between 1 and 4 after turning the timer. Turn the timer until it clicks and check continuity is no longer on 1 and 4 and should be on 1 and 2. Mark all the connectors so you can install it back correctly. When the timer sends voltage to 4 is turning on the compressor and 2 is turning on the heater. I think that the issue would be related to the timer because it seems to be heating to reduce the ice on the evaporator but not quite. Or the heater is not heating.
Where is the timer & how do I get to it? Brian
It isn't on your diagram? I'll let you know soon I'm reading some bedtime stories. Sorry for the delay.
So sorry, I dozed off after reading! The defrost timer would be near the bottom. Follow from the compressor probably near the side. Looks something like this:
Turn the dial on it and at the end it clicks. Test 4 when in between timer click and to test 2 when it clicks at the end. If you have continuity when testing 4 just turn the dial until you don't have continuity then test 2.
Any progress on testing the timer?
Hi Mike, I'm afraid that between work and getting ready to visit my Mum I've not made any progress since. It will be Monday before I can carry on. Thanks for your efforts thus far. Brian
You are very welcome. I am quite confident that the timer will be the issue and you can still ask questions even after rating my service. I will always respond. Mike
Hi Mike, Firstly, I apologise for disappearing for a while without telling you what was happening. To be frank, I came to the conclusion that you were making suggestions based on a probably older generic fridge freezer rather than expertise concerning my make and model. Your last suggestion was that I check the defrost timer, and you expressed confidence that this would be the problem, but my fridge freezer does not have a defrost timer. Instead, I did what with hindsight I should have done in the first place, and got hold of a service manual online.
Having read the service manual, I had a look at the main PCB (behind the control panel). For your information, this is where the relays are that control the compressor and the defrost system, and the resonator and integrated circuit that provide all the timing. This PCB had no obvious problems. When I checked the resistances of the loads I found the defrost heater circuit was 1.95 kohm. At UK 240 V mains this works out at about 30 W, which matches the three minor heaters, so the 310 W main defrost heater must have been open circuit. This I confirmed when I checked this heater directly. Unfortunately this heater is integrated with the evaporator and the combined part costs 83 GBP. A repair would also require professional to replace the evaporator at significant extra cost. (I’m aware of a potential DIY fix that I’ve seen online, which involves separating the new and old parts so the new heater can be fitted to the old evaporator in situ, but this has significant safety implications and I wasn’t prepared to attempt it.) When I started this exercise I thought the unit owed me a few years of life yet but it seems that seven years is about par for a modern fridge freezer, particularly a frost free one. Therefore, we have ended up buying a new one.
In terms of the symptoms exhibited by this appliance, it might be that there is a second fault. However, my strong suspicion is that whereas most manufacturers use an integrated circuit to make an appliance more intelligent, Samsung have used it to build in stupidity. When switched on it does some kind of self-test routine, which may be detecting the fault. Or maybe it just times out when defrosting. The clever thing to do would be to flash the 5 front panel LEDs to attract attention to the fault while carrying on freezing for as long as possible. Instead, the unit switches off so that the food in the freezer thaws out and is ruined. My switching it off and on presumably meant that it forgot that it had been timed out on defrost, so it carried on freezing until the next defrost was due. The mode that I had forced it into is mentioned in the service manual; it’s a test function which can give forced freezing or forced defrost.
Thank you for your efforts, Mike, but I don’t think your suggestions helped me to identify the fault. Best Regards, Brian