Roland Cube 20XL as Dead

[RuiCosta]

Hi, I have a Cube 20XL. It's from my guitar teacher. He wanted to put a switch on the circuit of the headphones to disconnect the speaker from the amplifier and when trying to solder the switch had the amplifier turned on the power supply went out of power. He turned off the led and never touched it again!
What could have burned?
If anyone knows, I would be very grateful.

[The Dude]

Here's a schematic for starters.

http://music-electronics-forum.com/a...be-20x_30x.zip

My best guess is that a fuse or fuses blew and the output device shorted since he likely grounded the output presenting a direct short to the amp. This amp uses a TDA2050, so I'd check that for shorts. You might even see a giant chunk blown out of it. It's also entirely possible that a fuse blew before any damage was done. You'll, of course, need to open it up and check.

[Enzo]

The headphones jack should turn off the speakers anyway, right? So no need for a switch.

I'd agree, messing with the speaker and phones circuits is a good chance you burnt out the TDA2050.

[RuiCosta]

I think he wanted to signal a mixer and continue to listen to the guitar on the amp. Then I put a switch to turn on the speaker circuit that turns off when I plug the jack.

[RuiCosta]

Sorted out.
It was F2 and F3 of 1.25A that burned. The scheme was of great help. Thank you friends for the great help.