Tandberg mystery bulb in power supply

[latala]

Funny you should say that! You know how some times you need three hands i can remember putting the hot end of the iron in my mouth burning both top and bottom lips
Ow never did it twice
Fond memories
Trev

 

[PRR]

...have isolated the fault (I think) to the phono/input board.....

That is odd. The only power path on the phono board is through 1K resistors R331 R332. 25V/1K is 0.025 Amps, which is much less than a 12V 4W (0.3A) lamp needs to get hot.

So stray wire-strand?

 

[Kay Pirinha]

...a quick kiss of the soldering iron and all was back to normal

Are you really so in love with your soldering iron?
Best regards!