A500 mouse/joystick problem

[BosonMichael]

I've got a problem with my Amiga 500. The Joystick 1 port seems to be having problems. Here's what happens:
 

Joystick:

• button works
• hold stick L, cursor moves up 1 pixel; release stick, cursor moves back down
• hold stick R, nothing happens
• hold stick U, nothing happens
• hold stick D, cursor moves right 1 pixel; release stick, cursor moves back left

Mouse:

• connecting it causes Workbench bar to flicker between "Workbench release/free memory" and "Workbench Disk Special" drop-down menus.

Keyboard works fine.
 
I swapped the CIA 8520 chips, but the problem does not change. Any ideas?

[BosonMichael]

Thanks to both of you. I'll reseat Gary and Denise and see if that helps. If it's a soldering issue, I might as well bury it or sell it for parts, because I cause more problems than I fix with solder. I wouldn't even know where to take it to get it fixed.

[BosonMichael]

That all depends on where you live!

Aha! Thanks for that, fixed my profile. I'm near Nashville.

[BosonMichael]

Hmm. I was just about to post that nothing happened after reseating Gary and Denise (and Paula for good measure)... but it looks like the behavior HAS slightly modified:
 
hold stick L, nothing happens
hold stick R, nothing happens
hold stick U, cursor moves down 1 pixel; release stick, cursor moves back up
hold stick D, cursor moves right 1 pixel; release stick, cursor moves back left
 
Wondering if I should replace Gary and Denise... obviously something happened...

[BosonMichael]

Thanks for all your help on this issue. I finally learned how to solder and tried out my new skills on replacing U15. However, in trying to remove U15 (man, that was difficult!), I damaged the component next to it - if I remember correctly, it's C15. Anyone have any idea what this component's specifications are?