Lazerhawk
New member
I left my games on for four hours and came back to them and Congo had no sound what so ever. Eventually I found out that one of the small caps C45/C46 was shorted, diode test showed a short in either direction. I bought some new ceramic disc caps from radio shack and replaced c45/c46 but in order to find the short I had to remove other components. I removed the 10k mf cap C37 and screwed up the negative side plated through hole so i ran a wire from the top and bottom traces and put it back in. Now the game sounds work but theres an insanely loud hum as soon as the game is turned on. I also replaced 79L05 because I thought that was what was shorted.
So looking at the schematic http://arcarc.xmission.com/Pinball/PDF Pinball Misc/Williams WPC-95 Schematics Manual.pdf page 8.. it says the c37 cap along with other caps and the 79l05 regulator should have a direct path to ground. I dont see that when testing with multimeter. I also dont see a trace that goes directly to ground on the board. Should I create a jumper to ground or tie the two negative sides of c36 and c37 together?
Is it possible that the through hole besides connecting the bottom and top trace also had a ground trace sandwiched between the board?
So looking at the schematic http://arcarc.xmission.com/Pinball/PDF Pinball Misc/Williams WPC-95 Schematics Manual.pdf page 8.. it says the c37 cap along with other caps and the 79l05 regulator should have a direct path to ground. I dont see that when testing with multimeter. I also dont see a trace that goes directly to ground on the board. Should I create a jumper to ground or tie the two negative sides of c36 and c37 together?
Is it possible that the through hole besides connecting the bottom and top trace also had a ground trace sandwiched between the board?