Please help. Samsung SR-S20. Need to replace thermo fuse and defrost sensor

[mitch98]

Hi,

I need to change the thermo fuse and the defrost sensor on my samsung fridge/freezer. Can someone please help me and tell me where to find these parts on the fridge. I have bought the part on the internet already.

Many thanks

[tonto33]

take all shevles out fridge remove white screw on light cover that 3 screws under that remove slowly disconnect wires behind panel then remove 4 screws for big panel at bottom then u will see were the parts fits

[paul_h]

sr20 has the evap only in the freezer I think, single coil, air ducted to the fridge, sr21 is dual evap. Does the fridge say "twin cool" on it in the fridge somewhere? If not then the parts go in the frezer section.

So strip out the freezer shelves, and remove the cover over the inside of the freezer.

[mitch98]

Hey Guys,

Thanks for the help. I managed to get the parts changed, but the problem still persists. The display is showing one temperature but it is much warmer inside.

Has anyone got any other suggestions as to what might be the problem.

Many thanks

[paul_h]

Heater might be open circuit (same effect as blown thermal fuse, no power through defrost circuit). Fan may not be working properly, temp thermistor may be faulty, PCB may be faulty.

edit:
Is that why you changed these parts, temp display wrong?
Could have saved you some time if you asked in the first place, a stuffed defrost sensor never causes that fault (wrong display) the defrost sensor just prevents defrost, causing icing up.
The wrong display is caused by defrost fault (ie, this fault can't happen unless the defrost sensor is working because no defrosts occur with a faulty coil thermistor).
So you hardly ever need to change the defrost sensor in this case, just check the heater and thermal fuse for continuity and make sure the fan runs in all speeds..

[mitch98]

Hey Paul,

Thanks a lot for the advice. How would I go about doing the checks required? I am quite handy but not an electrician or fridge mechanic. Is it possible for you to explain to me how to do the checks?

Would be a great help.

Many thanks

[mitch98]

Just to clarify:

I you set the temperature on the display, it goes down to that temperature, say -16 and 3. If you come back 4 or 5 hrs later the temperature says that it is -16 and 3 but you open the door and it is clearly not. So you switch the power off and then on and it show the real temp. possibly 0 and 9. Very unreliable.

Thanks

[paul_h]

As I said, make sure the fan works, ie open the door, make sure the fan runs for a few minutes blowing air out the vents while you hold down the door switch for a while (test for a few minutes as theres a few speeds it runs at)
Use a mulimeter to check the resistances of the heaters.
The bad display is only caused by a mains control circuit being cut, a faulty defrost sensor (or coil sensor as I call them) doesn't cause this problem.
If the fault occurs initally after a full day and night of running after power is reset, I bet defrost circuit fault (heaters, thermal fuse). If it happens the same day after power is switched on, I bet fan fault.
Is it a twin cool or single evap?

[mitch98]

Thanks again for the help Paul.

It is a twin cool.

It does definately get down to the temp it should be at but somewhere along the line it decides to heat up again.

If I hold the door open and hold the door switch down there is no air coming in through the vents at the back. It sounds like something is trying to start... The fan at the back of the fridge sounds like it is running, if it is a fan.

It does seem to happen gradually, if you wait about 5 hrs and switch the power on and off the display shows that it is actually warmer than it was before you put the power off. If you leave it over night it is up by about 14 degrees.

[tonto33]

check fan inside fridge

[mitch98]

The fan seems to come on but now cold air coming in. The fan in the freezer seems to come on and it is cold. There doesnt seem to be any speed change in the fan though.

[mitch98]

It seems to get to its temperature then switches off. I am sitting infront of it now and it has completely stopped. I think that the problem is that it doesnt come back on again after it reaches its desired temp.

[oweno]

a samsung rl39sbsw I'm trying to fix for a mate is doing something VERY similar.

- have confirmed that the compressor & evaporator are chilling nicely - the fan runs. the flappy bit that directs the air to the fridge works..... leave on for an hour or two all seems good.....

next morning - fridge and freezer compartments are warm and compressor is stone cold (so hasn't been running)

I'm thinking it gets into defrost mode but never comes out of it...... question is - is it the main PCB with the timer on it - or could it be something else ?

(have metered the freezer thermistor - about 5k ohm at ambient temp and changes as expected with hand heat)
(the heater near the the flappy bit measures about 10k ohm too. seems a bit high for a heater - or is it just another thermostat covered in foil rather than being a heater ??)
(the circuit diagram on the back shows a thermal fuse in the heater circuit - anyone know where this hangs out ?)

(this model doesn't have the fancy temperature display on it but everything else on the surface of it sounds the same)

O.

[bazzey]

Hi everyone I have a similar problem with my samsung srs2028 with the fridge and freezer warming up.

There is heater and thermo sensors in both compartment and reading from all the response on this thread suggests defrost circuit is where my problem is but how do I establish which one?

Are both defrost circuits linked that if one does not work it shuts down whole thing waiting for a manual start?

[spimps]

Hi everyone I have a similar problem with my samsung srs2028 with the fridge and freezer warming up.

There is heater and thermo sensors in both compartment and reading from all the response on this thread suggests defrost circuit is where my problem is but how do I establish which one?

Are both defrost circuits linked that if one does not work it shuts down whole thing waiting for a manual start?
Usually Yes !