Problem: Plays but slot 2 has sound issues and only slot 2 does it. The rest of the slots work fine. High pitched humm sounds when a game starts and the music changes to a higher octave it doesnt humm on a low sound.
Tests Performed
1.) Cleaned slot 2 with deoxit and tried different carts.Problem still existed.
(2.)Tested Caps in sound section of lower board and caps tested good. Reflowed the solder on all caps in sound section.Retested problem still there. (3.) Starting near slot 2 on the upper board then using a multimeter on continuity I started checking for broken traces. The top of the board looked good so then I flipped the board over and after an hour found 1 bad trace under the black padding{Man I hate that crap]. Repaired the traced and figured I would test it. Put the board back together and now slot 2 is fully playing again with no hummm out of slot 2.
Solution: Repaired broken trace near A10 on top board coming off of pin 10 on the 74LS244 IC chip.
pics show the location of the bad trace.
I ordered some green 30 gauge kynar wire wrap for future repairs so they blend in better with the board color.
Tests Performed
(2.)Tested Caps in sound section of lower board and caps tested good. Reflowed the solder on all caps in sound section.Retested problem still there. (3.) Starting near slot 2 on the upper board then using a multimeter on continuity I started checking for broken traces. The top of the board looked good so then I flipped the board over and after an hour found 1 bad trace under the black padding{Man I hate that crap]. Repaired the traced and figured I would test it. Put the board back together and now slot 2 is fully playing again with no hummm out of slot 2.
Solution: Repaired broken trace near A10 on top board coming off of pin 10 on the 74LS244 IC chip.
pics show the location of the bad trace.
I ordered some green 30 gauge kynar wire wrap for future repairs so they blend in better with the board color.
