Ampeg SVT-5 pro channel problems

[tonepumpamps]

I'm working on an Ampeg SVT-5 pro with no output.
I plugged straight into the power amp section and that works fine. My trouble seems to be in the channel switching circuit. I have signal til then.
Both the clean and overdrive LED's stay on all the time regardless of channel switch setting. I'm having trouble finding the trouble spot.
I was wondering if anyone has had some experience with this circuit.

Thanks!

[Jazz P Bass]

Start at the LEDs.

Work your way find to find why they are alwas On.

Hdr J4A (Switching): what is going on there, voltage wise, when you try to change channels?

Prove that Q20 & Q14 are good.

You also have to rule out a fault at the footswitch jack.

SVT 5 Pro Switching.pdf