Miele Condenser Dryer T7760C Act.Care - any program stops and shows "KaltLuft" with buzzer

[SergChuk]

I have being cleaning my old Miele Dryer as it were so much fluff gathering inside that water never evaporate from inside (even after 2-3 warm air cycles 20 min each without cloth).

After I have gathered the unit together (holla to saint German engineers ho made things intuitive) and starting it up I get every time and on every program 1-2 minutes of rotation and heating and then buzzer starts to operate + on the screen I get "KaltLuft" sign. Unit continues to rotate. 

Usually I had this sing with buzzer and after pressing START/STOP -> unit was switching mode to "Ende" and buzzer went off. Now it do not react to anything for some minutes.

1. Could it be doe to completely dry unit without clothes?

2. Could it be some sensor returning wrong info? I tend to thing that one of 2 TEMP sensors are not correct or working. First - I overheated the heater after assembly = I didn't install condenser+front door and so there was not enough air flow through heater. It went red hot (looking through drum inside) and started to make sparks to casing. I switched the unit off as got the idea what is wrong. Maybe protection sensor is dead and so I overheated measuring sensor? What is strange - unit didn't went off with sparks and red heater.

3. Maybe I also was washing the door with sensor in it with water and sensor went bad (I think that is just a resistor sensor so nothing to damage with water - but maybe I was wrong with it)? 

I still didn't test my dryer with real wet stuff... maybe it is not dead. But would like to get advice on that + schematics or any service manual to help figure out my sensors state.

 

Thank you.