help with Laney pro tube

[Valvehead]

Trying to figure out this amp -- its a Laney pro tube 100 . Its NOT the series 2 version.

It wont switch the preamp 1 tube stage. That is on a push/pull pot .

the LED light doesnt work and the Preamp Level 1 pot has no effect.

the footswitch jack doesnt function

i replaced the 2 H11F1 chips and also the 2 transistors.

the LED light does work if i touch a battery to it .

any help would be great !

[Gtr_tech]

Sounds like the low voltage that powers the optoisolators is missing....
The mid 80s schemo I have shows them running the optos off the bias tap with a seperate rectifier and 1000u filter cap to generate a positive voltage.

[Valvehead]

thank you sir -- found the problem.

the diode after the bias supply = one end had NO solder in the joint ! Nothing .....like the factory missed that hole !

works great now