contour and bass not working on boost channel Marshall valvestate 4080

[JL25]

I recently got a valvestate 8040 and the bass and contour don't seem to be working on the boost channel. I have a possible small gig on friday September 27th and need help. Anybody got tips?

 

[Jon Snell]

Check TR1 is switching ... assuming the boost light is working.

 

[david_clough]

I have same combo, it's a good item, mine suffered from dry pots, needed to replace some.
No bass or contour knob control >might< just be the pots. If you have the right contact cleaner, it's worth giving them a quick squirt (up the inside).