Gallien-Kruger 400RB 2x10 combo problem, no signal to speakers.

[jbow]

You will be amazed what you will learn with a tracer (or scope) and a schem. It will open your eyes to how to follow the road map through an amp.

Thanks, I looked at some signal tracers, they are all over the price range and I don't know what I should get. I cannot justify spending 1k on it. I may pick up a good used oscilloscope. It should be an adventure!
Thanks,
Julien

[J M Fahey]

If you have a notebook you can have the functional equivalent for less than $20 in parts, which are the "special cables and probes"

Yesterday night I installed a nice free piece of audio testing software , including scope and generator, this night IŽll make the cables, probably tomorrow I can post something about it.
Stay tuned.

[52 Bill]

Sorry but the Tuner jack is an output only.
If you try to use it as an input, signal will try to get in through a 100K resistor and will be swallowed by the discrete Op Amp's low output impedance which is always connected to it.

I'm sure that you are right here, but it wouldn't stop me from trying it.

[audiopete]

You can make one - Billm Audio » Troubleshooting your amp with audio signal tracing

If you are going to get a scope, then go for that. It will be more useful. This one is very well regarded for the money (under US$400) DS1052E 50 MHz Digital Oscilloscope | Rigol - Beyond Measure

[jbow]

Thank you for all the answers. Life happened and I had to step aside. It may be a few weeks or more before I can get back to it. My dad got sick a couple of times and then again last Monday. He passed away on Thursday. He was 96. My mom is 97 and still at home under hospice care. She has dementia and does not yet know he is gone so I don't know what life holds for the next days, weeks, or months.
I'm sorry I have not kept up but I will be back when I can to take this up again.
I am OK!
Thanks,
Julien

[Jazz P Bass]

Sorry for your loss.

Wow! 96.

[J M Fahey]

Same here

Go hug your Mom, that will get to her straight heart to heart, no strict need for a 100% working brain for that, if you know what I mean.

You will also get comfort from her

And, as they say, Life goes on.

Here a bunch of Friends waits for you whenever you want to come back

[g1]

Glad to hear you're OK.
We'll be here, no hurry.