Your JamMan has an external power supply, and inverter might have killed it, so in principle you should try another, same specs.
But reading the user manual, I see itīs not a full "power supply" but just a mains to 9VAC "Transformer" , a different beast , which might have passed the wrong voltage to the real regulated power supply inside your pedal.
If you killed that, itīs beyond average user skills range, youīll need a proper Tech.
Try the brick power supply on its own, measure the output plug to check whether you have 9VAC there or not.
If not, maybe thatīs all what happened and a new one will work; if you have proper voltage but JamMan shows no signs of life, not a single Led lights, noting, then itīs Tech time.
Ps: you might open it and post a picture of the area around the power jack, you *might* have a clip on fuse there, but not too hopeful, lately factories prefer polyswitches and similar protectie measures rather than antiquated glass fuses.
IF you have a blown fuse, replace it with ***exact*** same type and rating, do not bypass it or use a larger one.