You raaaaaaang? 
I didn’t realize they had a button for this!!
Easy fix! Stop pressing that button! 
Seriously though…
Assuming you’ve already tried cleaning the 510, I would take a magnifying glass and inspect the 510 to make sure that there’s no metal fragment shorting the center pin to the outer portion.
Aside from that, I’m more than happy to have a look inside if you want to send it…
All this time and you haven’t seen my avatar?
(hint: there’s a movie reference involved)
Hey man, I would more than love to send this to you. I’ve screwed the solder up anyway, it can be fixed but solder abilities or zero. Maybe it’s because my hand shakes a little, but even when I was a kid, I couldn’t solder. Can you pm me your address?
I absolutely love this mod.
Probably one of the greatest movies ever. Don’t even think my wife has seen it, but it is more of a “guy” movie.
This never makes a tech nervous… 
lol
Proper heat is key. As long as you didn’t melt anything… Like ohhh say the 510 insulator, or important chassis parts…
Seriously though, from the sounds of what you’ve described, I’m hoping things should go smoothly.
PM sent!
Just don’t grab Cutlass92’s (plumber boy) acid core solder! 
Just in case you or sprky can’t fix it, here’s a bf deal on it. Only on the silver leather so, code vj10 gets it down to $24.30. No idea about shipping or how long that deal will last etc, just thought I post it here.
I’m wondering if EVERY 300 that has this issue has actually had their solder removed or out of place. Could be a real easy answer for a fix that everyone has.
straws? Grabbing?
I’d be surprised.
I’ve had both mine apart and didn’t notice any physical issues with the 510. That would have been too easy!! I wish.