Bosch KGN36A73 Refrigerator - Alarm, LED Constantly On, No Cool Air in Upper Section

Hello.
The alarm went off in the Bosch KGN36A73 refrigerator (the diode and the sound as if the door was open). After some maneuvers, the sound was turned off, but the LED was constantly on. After a few days, it turned out that the freezer was cold and the top was not cooling. When I read about similar cases on the forum, I decided to dismantle the evaporator housing and it turned out that the entire evaporator is in a block of ice.

After defrosting and dismantling, it turned out that the heater is working (probably from No Frosta), the temperature sensor as well, so my suspicion fell on the lack of power to the heater or a problem with the heater control. Then I also noticed that the refrigerator had not been firing for some time, i.e. it had not made noise every now and then (it was not heard at night). Can anyone tell me what and where else can I check?

Regards
volume

And the heater fuse is working? If damaged, the heater must also be replaced.

Where to find this fuse (from the heater)?

Greetings
volume

The fuse (brown in color) is attached to the rear of the evaporator with strips.

After disassembling the evaporator, there was no fuse on the ankle to heater wires.
on the rear wall of the freezer, behind the evaporator, there is a rail with four colored cubes attached (fig. 2):
- white - connected to the evaporator tube (photo No. 2)
- black - connected to the heater
- blue - connected to the fan
- pink (orange in the photo) - sensor between the evaporator fins (probably the temperature) (photo no. 1).

Resistance value on individual cubes:
- white - break
- black - 240?
- blue - 31M?
- pink - break
What else can I check?

gatik wrote:

- white - connected to the evaporator tube (Fig. No. 2)

This is where the thermal fuse is located and from what you write it is damaged.

gatik wrote:

pink - break

NTC got breaks or calibrated and the electronics turned on the heater for too long, as a result of which the thermal fuse fell.

So I understand that the TNC temperature sensor needs to be replaced, which is located between the evaporator fins (in the shape of a white cylinder) connected with a pink cube and a thermal fuse that is connected to the condensate supply pipe with the evaporator (in the shape of a brown cylinder - attached with bands in the photo)

Gentlemen, this topic is as old as the world, but I am not sure about my fault, so I will refresh a little.
The topic looks like this:
I have a refrigerator as in the topic (KGN36A73 / 01), the symptoms are exactly the same as with my colleague above, for the first time I had a problem about 3 weeks ago (we have had a refrigerator for 5.5 years), i.e. squeaking and ALARM. And now my brother-in-law who bought his one month after mine and the KGN36A94 / 07 model with stainless steel sides (I have varnish) has the same thing.
As I wrote for the first time, the fridge gave a sign of failure 3 weeks ago two days after her sister-in-law called that her fridge broke down. As after two days, I had exactly the same thing, I considered it a coincidence, but ... My sister-in-law called a service technician, he came, he did nothing, ordered to defrost for at least 36 hours. My sister-in-law did so, and I followed her advice without calling a service technician in exactly the same way. Well, the refrigerators started, after about 14 days, that is, last Sunday, a phone call from my sister-in-law that Bosch was yelling again and "ALARM" was on, and the freezer was all covered with ice from the top, the rest was frosted. And now the funniest thing, the fridge woke me up at night around 2 pm. and exactly a copy from my sister-in-law's fridge.
My hands dropped so browsing the forum and I ran into this post, now measurements.
Refrigerator KGN36A73 / 01
red cube (sensor in condenser fins) - break
white cube (brown thermic) - measurement 33.9 MOhm
blue - the fan is operational
black - heater measurement 240 Ohm (i.e. OK)

Refrigerator KGN36A94 / 07 (sister-in-law's fridge)
red cube - 24.3 MOhm
white cube - 12.6 MOhm
blue - the fan is operational
black - 240 Ohm heater (like mine)

My guesses are based on browsing through a few topics on the forum, that both the thermic and the sensor in the evaporator are damaged (their readings should be close to 7 KOhm at room temperature if they are working properly). Am I right?
And now the spare parts:
Termiki, i.e. white cube, costs about PLN 82. and they are the same (links below)
http://north.pl/karta/bezpiecznik-termiczny-do-lodowki-bosch-kgn36a73;01,9SD-VS-CMMP-1TN.html
north.pl/karta/bezpiecznik-termiczny-do-lodowki-bosch-kgn36a94;07,9SD-VS-CMMM-LNM.html

As for the sensor (red cube), it is not listed for my refrigerator, but it is on the list of parts for my sister-in-law's refrigerator:
http://north.pl/karta/termistor-ptc-parownik-...odowki-bosch-kgn36a94;07,IRD-VN-CMMM-LNM.html

Can I use one for me? it is exactly like mine, identical (but it is not a temperature sensor, but an evaporator thermistor), i.e. a thermistor. The point is that I do not know about the parameters of these elements in good working order, but if they are thermal protections, their resistance should be as low as possible, right?
Is there anyone who can help me on this topic?

I did not finish the topic by writing that after replacing these elements, everything is OK with the refrigerator (until today .
It is certainly the same in your case.

My fridge broke after about the same time as yours. Considering mine, your two cases can be said that the service life of the products is "programmed", that is, the service life of certain elements is strictly defined and with high accuracy.

Regards and I wish you to deal with the problem quickly.

I have exactly the same opinion as you, it cannot be a coincidence !!! Fridges were bought about 1 month apart and died around the same time. Shocking !!! But it is calculated very precisely because I had an extended warranty for 5 years and the refrigerator broke down after 5.5 years. And how can you trust such a company? And my wife and I decided to buy Bosch to have peace for many years ...
Thanks for the answer . Regards !

I hope that the problem has been solved and the topic can be closed

hello, these sensors will fit KGN36A73? :

https://north.pl/karta/czujnik-temperatury-za...rki-do-bosch-kgn36a94-07,IRD-VN-CMMM-LNM.html
https://north.pl/karta/czujnik-parownik-do-bosch-kgn36a73-01,9SD-VS-CMMP-1TN.html

The first one is like for another Bosch model, but it looks the same ... I didn't find an equivalent for my model

Hi

How to check the fan?
On the blue cube, connecting the ohmmeter, I have no reading regardless of the selected range.

greetings
Gregory