@smeatr0n this is the repair carried out on the PCB (for this little fix, the board needed other repairs too).
View attachment 641058
The board had some areas reflowed, this was not the final solder this was tacked in, i pulled the resistor out and cleaned up the via on the top because when i desoldered the resistor it all disintegrated
View attachment 641059
A few reflows here and there as above, and just a little trace added on the underside as shown.
View attachment 641060
As confirmed earlier in the thread, the issue was in the marked area. With the board powered (and making a racket) I was getting 5v at R29, but 0.0v at the input of D6. Bridging the track and adding in a 1K resistor resolved the issue.