Liebherr freezer with deffective front panel controls and temp indicator

[conducteur]

Hello,
We got this Liebherr freezer from someone. The problem is that the temperature indicator and the controls on the front panel doesn’t work... (the compressor is presumably always on).

It’s not clear to me how to open this thing.

[soldar]

Ha! I got a two compressor refrigerator + freezer combo and the freezer has the same problem. In fact, I started a thread about it.

For now I have figured out how to disconnect the freezer compressor and have it on a timer. As soon as I get a new refrigerator I will attempt to repair this one. I am guessing it may have a stuck relay or a PCB that needs repair. If I cannot repair the original control I will just replace it with a cheap thermostat from eBay.

I will be following this thread.

[conducteur]

I suspect that there’s a power supply pcb in it that’s Not working... I have no experience with repairing freezers and fridges but the led and temperature control must operate from a lower voltage I think... I think there’s a relay in this thing to switch the compressor Off, but because the psu is brokken this control loop with the temperature sensor and the indicztor doesn’t work

[conducteur]

I’m in. It’s just a system with clips above the door to open it. The relay is rated at 24 volt... there’s a bridge rectificer next to the relay, but I only get 14 volts across it

[floobydust]

It uses a capacitive-dropper. Check the value of the big gray film capacitor, they go low value with age. The zener diode next to it can also fail.

But it might be short on the LED/control board which makes it draw too much current from the power supply. There should be around 24V unless the relay is on all the time, then 14V is OK.