RangeMaster – Interesting Intermittent Fault

Hello,

I would greatly appreciate another pair of eyes on the problem I have with my fridge freezer. Thank you

RangeMaster 661 – reskinned Haier 661
RSXS661SS/C

Fault: The fridge and freezer will initially get cold and freeze and work as expected. After multiple hours ranging between 12 hours to 4 days it will then warm up, not bringing on the condenser fan or compressor. Simply resetting the power to the appliance will bring back on the compressor and condenser fan to start cooling as soon as it “boots” up. It has been left in the failed state until it reached room temperature in both compartments and showed no signs of starting by itself.

I also tested if I was able to run it with just the freezer on (can turn the fridge off via holding the fridge temperature button) this ran for the longest time of 4 days leading me to suspect something fridge/sensor related. After four days I put on the fridge and 6-8 hours later it failed and started to warm up. Feeling like I was making progress I turned off the fridge again to prove my theory and this time it failed in the same manor with only the freezer.

Tested

Compressor – metered resistance, lower two numbers add up to the larger, appears to work fine.

PTC Relay – metered, in cold state it gives power to both the start and run terminals on the compressor. Not tested it switching, but appears to work fine.

Power to compressor – On metering it appears that no power was coming down to the back of the PTC relay when in a fault state.

Condenser fan – appears to be working perfectly fine – comes off and on with compressor although at one point was on but without power being sent to the compressor(not been the case for a long time).

Door switches – both the fridge and freezer door switches have been metered and appear to be working fine.

Evaporator fan – works fine, stops/slows with doors open.

Sensors- Most sensors at room temperature had roughly the same resistance

Fridge sensor 1 (top) metered has resistance

Fridge sensor 1 (bottom) metered has resistance

Freezer sensor – metered has resistance

Ambient sensor – metered has resistance

Evaporator sensor (top right) – metered has resistance

Evaporator sensor 2? What I assume is another sensor on the middle of the evaporator (left side) appeared to have resistance (although I have no idea what this one is looks like a long tube in some sort of rubber, mostly embedded into the polystyrene) Anyone know the purpose of the second sensor?

Heater coil below evaporator – metered out has considerable resistance

Fridge wind door trap – I am not sure how to test this, but I suspect it was working as I vaguely remember the fridge being cold enough and not having air blowing out the top (with door switch pushed in) Although not confident in this observation.

Display board – appears to work perfectly fine.

Icemaker not fully tested, however makes sound on pushing for ice. Also I am sure I can hear a value operating.

I have taken out and gained access to most of the device now, I am able to fully access the evaporator and sensors. I have not disturbed any of the pipe work.

Additional odd things I have observed:
The lighting has never worked in the fridge.
The lighting had sometimes worked in the freezer however most of the time it didn’t. Once by spamming the door switch the freezer light did come on. Both tested with good bulbs, I suspected door switches but they still had impact on the evaporator
fan and on metering appeared to work perfectly with around 1 second to adjust between made circuit to nothing.

I am starting to run out of things to look at and test, any ideas what could cause such a problem?

Service Manual for Haier version https://www.manualslib.com/manual/1055451/Haier-Hrf-661ff-Ass.html

Any help would be most welcome thank you,
Andrew

Full Model Info