Control module power seat issue W124 era cars

[E300D]

hello all

Recently been working on my 1992 500E.

Present issue is: Driver side only seat completely inoperable as well as dead telescoping steering wheel.

Checked and replace all fuses to copper ones.

Swapped around the K5 and K24 relays

Checked for voltage at the fuses box.

Removed and cleaned the seat switch

Checked for voltage present at the red wire powering the control module under the driver seat. PN 129 820 0126


Removed the seat and checked all motors with 12V source. All 3 motors working 100%

Now I need to focus on the Seat control module:

Took it apart and found no apparent blown up resistors or capacitors or a bad solder joint

I have no idea how to diagnose and check the control module.

Looking to see if anyone is able to provide some tips how to troubleshoot a bad seat control module

Already looking on ebay for a used replacement module but no joy

Regards
Sebastian