Hi Jan,
Thank you for your explanation.
I understand your reason for rejecting the PMC button. I was hoping to see HMC unit come in action but it would be a can of worm I suppose. While I am on the subject of the engine, I would like to ask that Boeing 737 classic have an approach idle mode? I used the anti-ice earlier and notice that engine rpm remained the same.
Regarding the cabin rate of climb issue. In my case, the cabin rate of climb was oscillated in cruise, as you can see in a picture below. It always oscillated in a positive rate of climb but strangely the differential pressure remain more or less the same.
In addition, I notice that the anti-ice switch for both wing and engine stuck in transit if I move it while the engine is shutdown.
Best regards