Ancient Electrolux Freezer EU1323T keeps running

[touran daddy]

Good afternoon all,

thank you again to all who help on this site as it has saved me a fortune over the years.

The problem I have this time is that my very old (15yrs ish) Electrolux freezer keeps running with the red fault light on and doesn’t respond to the temp adjuster on the front panel. Freezer is running at -30c or colder but that’s all my thermometer reads down to.
I am assuming there is a temp sensor to tell the freezer to turn off but would value all advice available.
I really don’t want to add to the white goods mountain of broken things as being an engineer it’s in my blood to fix/repair.
Model EU1323T
prod no. 922727768
serial number 13100139

many thanks for any advice given

Jez

[electrofix]

can only be the probe or the board

probe is still available
https://shop.aeg.co.uk/fridges-freezers/fridges-freezers/feet-housing/refrigerator-probe/p/2425071285

board is obsolete

Dave

[touran daddy]

Hi Dave, thanks for the info.
Any way to check the probe or suck it and see?
regards
Jez

[electrofix]

you can normally measure the resistance of the sensor at a given temp but there is no tech info to tell me what to expect probably due to age

it does say if there is a total failure of the sensor the board flashes 3 lights and goes into timed mode

Dave

[touran daddy]

Sound More like the board as it’s a solid red light, no flashing.
I’ll have it apart and check the sensor and look at the board and see if somethings given up. Other than that it may be time to lay it to rest. 🙁
I appreciate the info again
Jez

[electrofix]

try unplugging the sensor and see if it goes into timed mode

Dave

[touran daddy]

electrofix wrote:try unplugging the sensor and see if it goes into timed mode

Dave

Will do Dave thanks, I’ll let you know!

[touran daddy]

Morning Dave,
so yesterday I took the lid off and disconnected the sensor. The freezer is now flashing red fault light and seems to be working in timed mode.
the sensor measured 2.02K ohms at about 10c before switching back on. Circuit board appears ok visually with no burnt components or dry joints that I can see.
I checked it during the day and got these
2.07@4c
2.44@-7c
2.46@-13c
2.55@-22c
have I lucked out with a sensor problem?
thanks
Jez

[electrofix]

one long shot

dont know the board but the main compressor will either be controlled by a triac or a relay
if this component has failed it wont alow the board to turn it off

Dave

[touran daddy]

Hi Dave, looks like the board is triac controlled.
if the board registers a solid red fault like with continuous running with the sensor plugged in and timed running with the sensor unplugged and flashing red fault light can we assume it is out of range on resistance?

https://drive.google.com/file/d/18Gi1FmH51dhPMrgaFLgrYpbvY-yBeTX7/view?usp=drivesdk
https://drive.google.com/file/d/18HX2MLWZh-cjCyw9txeGqKkeTeGXtdGX/view?usp=drivesdk
https://drive.google.com/file/d/18AV_hZcoQGBX0_KwV-VSrjsP7XybMiCz/view?usp=drivesdk

[electrofix]

very likley but you can never be certain because we have not tech info

normally we get resistance values based on temp
your reading doen’t seem to move much.

from your reading the resistance goes up with temp going down
if it was me i would try adding a 1k res in series and see what happens better still if you could get a 5k lin potentiometer and ajust it 10 degees at a time and leave it an hour each time

unless you want to take a chance on the sensor

Dave

[touran daddy]

Thanks again Dave.
I had a look over the board with my x10 and found a dry joint on one leg of the triac so will reflow that then work on adding resistance.
I’m assuming I’m reconnecting the sensor but adding the resistance inline to increase the reading given to the board and see if the freezer shuts off?
https://drive.google.com/file/d/18V8YudJ5BUL2WQtfGfS0gz-9pQL_SNYP/view?usp=drivesdk

Jez

[electrofix]

correct am trying to see if the resistance was higher then is the board capable of controlling temp

find the right resistance and it may be ok

Dave

[touran daddy]

Hi Dave, I didn’t have a variable resister so I ripped some resistors of an old CB I kept and threw in a 14k ohm no joy, solid red light as before and cooling down past -22c
46k turns off the fault light and the freezer was at 2c this morning but that could be natural cooling down not maintained.
i have both running in series to see what happens next.
some of the old american freezer tables suggest nearly 80k ohms for around -15 ish but connecting 2 46k in series didn’t start the compressor.
this is all with the temp control dial set at -18c.

Jez

[electrofix]

the problem here is always going to be that we dont know the original spec of the NTC so we dont konw its working range

in the end if you cant find a resistance that works you will have to decide if you want to take a chance on the sensor

Dave

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