I have a dual recliner sofa that is dead. No power recline, no lights in the buttons, no power to the USB ports. The power adapter's green LED indicator is a strong steady light when just plugged into the wall, but faintly blinks every second when it is connected to the sofa. As far as I can tell, all the wires are sound and the connectors are secure. Does this indicate a dead motor?

My father recently had surgery and the power recliner we bought him for recovery (a Human Touch Perfect Chair model PC 009) has developed a partial malfunction: when pressing the switch to recline, I can hear a relay clicking but the chair does not move. The chair is quite expensive, and I would love to repair it for him if possible.

Imgur album with multiple views of the PCB, motor, and other parts here.

I've removed the motor and box containing the electric components, and checked the following obvious points of failure:

1. The fuse near the mains power has continuity

2. The arm rest switch recline switch is working - I get continuity between two of the wires coming from it when pressing it to recline

3. None of the capacitors are blown - no obvious external damage or leaked juice

4. Power reaches the transformer, and low voltage power reaches the IC

5. The wires connecting the motor to the mainboard have continuity (they appear to have been cut and rejoined with heatshrink, but I get clear continuity between the motor terminal and the traces on the PCB)

6. The relay activates when the circuit is powered and the recline switch is activated

7. There is no other obvious damages to the components on the PCB, with the possible exception of one larger resistor (which appears slightly darkened perhaps due to excess heat, and the solder points on the underside of the PCB also appear darker than the rest). However, measuring it with multimeter, it does appear to provide the 20 ohms resistance for which its rated.

8. The pair of limit switches that detect when the worm drive is at its furthest extents appear to work - one is currently closed, as the worm rod is fully retracted, and the other is open in this position.

I would appreciate any theories for what might be failing, or further diagnostics I could perform with a multimeter that would isolate the problem or lead to a testable theory.

Other details:

PCB is marked KD420C and HAUTE 050222.