Thanks for taking the time to look at my soldering, and for the compliments on my twisted wire.
I just trimmed the bare wire at the headphone jack. I don't think it should have anything to do with the voltage problem since the joint itself looks solid.
The wire on B3 just barely pokes trough about a mm upwards, but as far as I can tell it is soldered on with a good amount of shiny lead that fills up the hole. It also feels completely fastened and I reheated it earlier as well.
The insulation on the wire going in to 7 is right up against the terminal, but I don't think it's in the actual hole. It feels stiff and completely soldered on when I wiggle it and the end is wrapped around the terminal itself. There is no free play in the wire.
I will try your recommendations before I send in the amp. The capacitor on 9 and 10 feels loose when I wiggle it, but I know it is soldered on, so it has to be something with the capacitor. The capacitor closest to the RCA connectors made a loud bang when I reheated it, but it seems to be working just fine and giving correct Voltage readings on terminal 21. Maybe I should replace it anyway since I've heard that capacitors that get short-circuited tend to have a reduced lifespan.
I'll update you on my progress later, but if I can't fix it over the weekend, then I probably will send it in. How is the repair backlog at the repair department?