Crate fw120h won't switch to clean or high gain channels from the head

its the reverb tank spring, look where it is connected on the other side. this will give you an idea as to where it was connected. solder it back on.

Reverb spring end broke. you can bend a new loop with pliers. There is a post sticking up in side the metal case that hooks around the end(s)

That is probably a momentary switch that is dirty and sticking. These onboard effects on guitar amps are usually nothing more than a computer sound card and I've found bad connections going to and from them as well. I do think that switch is dirty and sticking, though.

Both those LIKELY run on a 5 volt supply within the unit. Check for the presence of that voltage... some new stuff MIGHT be 3.3 volts DC, but you should find those voltages. If missing, it may be a shorted electrolytic filter cap OR the filter cap associated with creating the 5 volts from the supply. You really need the schematic for this... try to procure one.

Solid state amps are very subject to blowing out the output transistors if speaker leads get shorted. Take it in for repair.

Hi there,I have the same problem with my flexwave 120. I opened the amp to measure several capacitors on the small effect circuit board. If one of this capaciters have internal short circuit, wich will effect the others causing effects to fail. I removed them one by one to find possible short circuit. All capacitors were ok. I think the problem is in the processor wich is to diffucult to replace. I think it's easier to replace the effects circuit board. But where do we find this board??

sounds to me like your din plug on your controller is messed up ? hope this helps !

It sounds like the DSP processor is either about to go out, or is mostly there. Have a qualified amplifier technician take a look at the DSP. Also look up the cost of a new one.

Hope that helps!

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/cameron_463100ffd54b591d

Josh,

I also need schematics for this amp. How about whoever finds it first shares with the other?
Cool, Thanks,
bob at stumpweb.com

There are 2 channels, Which means there are 2 sets of knobs ... One for clean and one for crunch. Start out with a low master volume and set up the crunch, Then the clen and switch between the 2 and make adjustments until they match volume wise ... Then turn the master up.