I had an issue on a Bally after a swap where the braid that supplied power to the sockets didn't make a complete loop. I found the break and connected it and some bulbs that were lit went out and some that wouldn't light started working.
The incomplete loop left some floating voltage on the line and the bulb is using it.
Just a thought
Edit: when I thought I found the break I used a jumper to verify it before I soldered the break.