K8081 kit - high bias reading across R42

Kits Audio Hi Fi Projects
1

Have assembled two K8081 - one without incident and one I have an error with.
On the second unit I initially installed D11 reversed - this resulted in some ‘heat generation’.
I have therefore replaced ALL semiconductor components (transistors, diodes) on the power amp section with new (identical) components. Now, on power up, the unit seem fine and passes test and generally behaves according to instructions.
However the bias voltage across R42 is now approx 250mV at minimum setting of RV1.

My questions then are:
What in general should I be looking for?
Are there other components I should check/replace?
What changes could I make to help alleviate the problem?

I am of medium knowledge level with electronics circuit theory.

Thank you in advance for any suggestions you can make.

Frank C.

2

At this time, your quiescent current is 500mA instead of 30mA.
This is way too much. We suspect a problem in the bias circuit.
Check BE voltage of T7, check resistors of bias circuit.

3

All resistor measure as specified in manual.
Several measurements of bias voltage T7 gives 0.40 - 0.42V

Again thank you for your time

Frank C.

4

This puzzles us.
How about the differential amp section.
Can you compare voltages with the working version?