I am bringing a Williams Lucky Seven (System 3) back to life, and almost
have it finished. My remaining problem is that none of the special
solenoids (2 pop bumpers and both slings) will fire in game play -
although they fire correctly in diagnostics. Power supply has been
rebuilt, getting all good voltages; 40-pin connector replaced; all
socketed chips have had the old sockets replaced with new machined
sockets; new 5101 chip; new 7402 and 7408 (although used 74HCT08s due to
no 7408s locally) chips on the special solenoid section of the board;
all other driver and pre-driver transistors check out OK; all 3 PIAs
replaced and socketed on the driver board due to other issues. If I
ground the tab on the TIP transistors, the solenoids fire and also if I
ground the inputs on 2J12 and 2J13. I really thought changing the 7408s
and 7402s would do the trick. Any suggestions/thoughts? Thanks in
advance.
have it finished. My remaining problem is that none of the special
solenoids (2 pop bumpers and both slings) will fire in game play -
although they fire correctly in diagnostics. Power supply has been
rebuilt, getting all good voltages; 40-pin connector replaced; all
socketed chips have had the old sockets replaced with new machined
sockets; new 5101 chip; new 7402 and 7408 (although used 74HCT08s due to
no 7408s locally) chips on the special solenoid section of the board;
all other driver and pre-driver transistors check out OK; all 3 PIAs
replaced and socketed on the driver board due to other issues. If I
ground the tab on the TIP transistors, the solenoids fire and also if I
ground the inputs on 2J12 and 2J13. I really thought changing the 7408s
and 7402s would do the trick. Any suggestions/thoughts? Thanks in
advance.