ishman SA330X XLR

[briconix50460]

Hello to you all,
I have a reference Fishman SA330X amplifier.
On the left channel, when I put the XLR it does not work.
Do you have any plans or troubleshooting ideas?
By thanking you in advance.
Regards

[The Dude]

What I see is a mono amp with a mixer input and what you're describing is mixer channel one is not working. If that's all correct and channel two works, we know the amplifier section works. First try to get a schematic and post it here. If you can't find one, I'd look for bad solder connections on the jack itself, then burnt resistors from jack to input op amp, then a shorted op amp just off that input. This is a crude description of potentials, but semi-typical problems with mixer inputs.