Unfortunately this problem has come back and stayed this time.

At the moment I have no sound at all and I've also lost the lights to the coin door and the 2 lower playfield bop bumpers.

I tested the fuses in the Rectifier board but t hey seem good but just in case I swapped in another spare rectifier board but this didn't make any difference. I also tried my spare Solenoid driver board and MPU but these made no difference.
I've had the squawk and talk board out, there is nothing obvious that's blown there. Any suggestions welcome. Thanks.

Check the voltages at the S&T board test points. You need +5V, +12V and -5V. What happens when you press the test button ?

Check the door globe holders. No shorts to Ground ?

Remove the door power connector and see if the pop bumper lamps return.

Sounds like 2 different issues.