Peavey XXX strange problems

[charetteelectronics]

I have a Peavey XXX 100 watt head in for repair. What is happening is the crunch chan. controls the ultra chan. unless first engauging the clean chan. first. All leds work properly and relay K3 is firing and switching properly (measured continuity). Any ideas ???
Many thanks
John

[charetteelectronics]

Sorry relay K3 does not change states with out going to clean chan. first

[Jazz P Bass]

Post the schematic?

[charetteelectronics]

Here is the schematic

[Jazz P Bass]

Thanks for the schematic.
I am not at all clear on what you are seeing.
If the Crunch & Ultra LED's are functioning then the circuit is good (Q7 & Q11)
If K3 has +17Vdc & the Ultra LED lights & K3 does not engage, that would indicate a faulty K3.
Is there any change in the symptoms between using the footswitch or the front panel pushbutton switch?

[charetteelectronics]

Ok here is what I found.
In Ultra mode
1.8 volts across K3
10.0 volts across K2

In Crunch mode
10.0 volts across K3
0.0 volts across k2
meaning logic circuits working correctly.
But Crunch EQ's still controlling the Ultra circuit.
K3 Relay contacts will not change states to Ultra unless clean chan. is enguaged first.
Started to suspect "lazy" relay.... replaced K3 and all working good now
Thanks for the advice
John