Why did my amp just crash and burn ?

Does the YBA have rail fuses?

These would be inside the chassis.

B

@gdnrbob The manual says fuse is located on the mains socket. 

Yes, I know.

But, sometimes amps have fuses inside for the rails.

I tried to Google your amp, but no pics of the insides.

So, if you replace the fuse by the mains, and it still doesn't work, then unplug and remove the cover and look for other fuses. They will probably look like the one on the mains, but probably with different values.

While your in there, look at the circuit board and see if there is any signs of damage (like darkened parts or soot, etc). Sometimes a capacitor might have blown. (But, I am of the opinion that you simply shorted out the speaker cables when adjusting- which is no biggie-other than changing the fuse).

Bob

learning moment: never touch any connections with the amp on, playing and connected to the speakers. You could damage the amp (maybe, most likely just a fuse) and could also, if you hit the wrong thing (say life an input ground) cause a noise transient that fries one of your speakers.  Its just bad practice.  Don't put your hand in a live socket, don't sharpern the lawnmower blade while spinning, and dont eff with your amp, interconnects or speaker cables while playing.

I find it amazing that people don't get these basics.

Now on to fixing it. I suspect what you did was short the amps outputs.  That means ti delivers X volts into zero ohms = infinite current.  Bzzzzzt.

It MUST have at least a line fuse. Hopefully sized to protect stuff beside your house. Side discussion - as a designer i see people who have partial shorts fix them by putting in a bigger fuse.  Let's not go there.

I would guess the fuse below. I would hope nothing else did.

replace the fuse WITH THE SAME AMPERAGE AND TIME CONSTANT.  BOTH MATTER.  e.g.: 3A slow blow (now often called "time delay"). or 5A fast acting. Or whatever it says on the back panel and in the manual (not necessarily what the fuse says since it could have been incorrectly replaced).

G

if yo need servicing I'm in the New Jersey NYC area.