Squealing / Drill -ish Sound from Amp.

[Jaoon]

Hey Guys,

so i finally tried to fix my old Valvestate vs100. Iam far away from an Expert. I can repair my guitars and stuff but never tried an Amp. So , There was no Signal coming from the Amp, neither from with a Guitar plugged in the Input or the Fx Return. So after checking a little bit i decided to solder Joints on the Powerstage Board, that looked like cold solder joints. Not smart at all i know. Anyway. After putting the Board back in, as soon as i turn on the Amp in makes this weird squealing/ drilling kind of Sound. Never heard something like this before. There also was a tiny bit of smoke coming from preamp tube area (i think). I dont know. Someone maybe know what this could be or what ive destroyed I added a Photo and marked the spot ive soldered
Thanks in advance

Edit:
It seems that i plugged con12 wrong back into the Trafo. So now i have no noise anymore, but still no sound and iam afraid, that i have burned a fuse (Smoke).

[Jon Snell]

If the photo is your actual amplifier, the issue in within the blue rectangle. Why have you got badly soldered joints that are shorting tracks together .....
Remove the solder, clean the pad and resolder using heat, fresh solder and speed.

[Jazz P Bass]

Lordy.
That is some poor soldering!
All over the place.

[Chuck H]

I once had to touch up a cold solder joint on my amp in the bands practice space, where I didn't have my bench tools. The owner of the space had some Radio Shack flux core solder but not an iron. I used the end of an unraveled coat hanger heated with a Bic lighter. It looked better than this.