Crate BT100 Bass Combo Amp Dirty Signal

[Hondamagnaryder]

Greetings,

Second post for this newbie!

I just fixed my crate guitar amp, and was celebrating, so a buddy asked me if I could take a look at his bass amp, so here it goes.

Amp Model: BT100

Includes: Distortion Channel, Clean Channel, and Master Channel with Octave option.

Problem when an instrument is inserted, into the input, rating for input switch is at 0db,

Distortion channel button is out so that signal is routed to the clean channel, but the signal that is heard over the speaker has distortion, almost as if the signal is still somehow running through the distortion channel.

I am at a stand still.

Cleaned Pots
Checked for any cracked welds
Made sure that all large caps are secured.

Schematic PDF is included.


Thanks for any help you can offer. I am stumped.
Harold

 

[JonSnell Electronic]

With your 'scope and a clean signal injected to the input, follow the signal backwards from the output stage until you get a clean signal and there will be the faulty component.

 

[dotneck335]

Dirty switch contacts. Common for Crate.

 

[Hondamagnaryder]

I'll get to both, and keep the updates coming
Thanks

 

[Sheuer84]

Hello, I'm having the same issue with my BT100. Did you ever figure out what the issue was? Thanks!