On the rectifier board, the copper around one corner mounting hole (the ground connection to the backbox) is worn away and will not take solder, and some header pins show cracked solder rings.
Early Bally SS rectifier board: worn ground mounting pad and cracked header pins
Cause: The mounting screw bites through the old copper over the years. The pad is only one of the board's ground paths; the header pins crack from age and heat.
Checks
- Check that the other ground mounting corner is in good shape and tight to the backbox.
- Look closely at the header pins (especially the power distribution plug) for cracked rings and tarnished plating.
Fix
- If the other corner is good the worn pad can be left as it is; if you want to restore it, clean the copper bright with fine abrasive, re-tin it, or solder a thin copper washer over the pad.
- Wick off the old solder from cracked header pins and resolder them with fresh solder and flux; do not just add solder over the top.
- If the header plating is worn, replace the header and repin the mating connector, and keep the standard ground and 5 V test-point jumper updates in place.
Systems
Related tips
- Replace browned rectifier header pins and housing pins together
- Rectifier board J3 pin functions (pre-Xenon backbox transformer)
- Burnt rectifier J3 pins 8 and 17
- Pre-Xenon rectifier board outputs by connector
- Pre-Xenon transformer to rectifier board wiring
- Only the GI lights and the MPU won't boot: bad connection at J3
- AS2518-18/-49 connector functions
- The three Bally rectifier boards
Source: Pinball Repair help group!! (Facebook group)