so essentially you messed with it and now it doesnt work ? ;-)

remember the heatsink compound when you put the board back in.
http://www.pinwiki.com/wiki/index.php?title=Bally/Stern#How_To_Properly_Mount_a_Bally_AS-2518-54_Rectifier_Board

now first what are the test point voltages ( d/c the outputs).
here you go .. read the guide and follow the bouncing ball
http://callkck.com/pin/BS7785.zip
then unarchive it and BS7785-1/index1.htm#ps

pretty sure you will know how to test a Bridge rectifier with a meter .. if not youtube has videos  ( remember its 4 diodes in a box) - Start there and go through the machine step by step