Removing Blockage in Refer Circuit

[Fazzy]

I let the DC on when I switched the AC on.
Older threads closed so I needed start a new one.

Refer model RM4223 by Dometic
Had been on the road too long so I didn't notice. The next morning refrigerator was warm. Went outside looked at the switches and noticed my mistake.

Turned off the DC switch. What I did notice was the first segment of the cooling fins right after the heating chamber was very hot and after that small segment there was no heat in the rest of the cooling fins.

Used my engineering skills LOL. That the ACV heating coil is controlled and the DC heating coil is 100% on only controlled by the DCV on switch. So my guess is I superheated the ammonia and created a blockage in the cooling segment just past the heating chamber.

I let it cool down completely for several hours. Since I didn't have a meter I just turned the AC switch on and I could feel the heating chamber warm up. AC heating coil was working.

I let it cool down completely again and with AC and DC off lite the propane. Set the propane thermostat to high and waited. Again only the first segment just past the heating chamber was hot but no heating in the remaining heat exchanger circuit not even warmth. No signs of yellow on the entire circuit so at least there is no evidence of a leak.

Called Dometic they could't tell me why they put that warning label on there about using two heat sources.

Any ideas on how to remove that blockage