andrewb
Well-known member
Get a logic probe and put it on the enable line for that sound. Make sure it's actually being triggered when it's supposed to be. (You should see the logic level change when the UFO appears).
If the enable is working, then the issue is somewhere in the sound circuit, and if you have replaced all of the parts (including Q6), check for cracked or broken traces, cracked resistors, and make sure all of the components are correct values per the schematics (as if someone else worked on it before you, people love to install incorrect parts sometimes). Also check R77, which is where the saucer sound connects to the output amplifier.
If it isn't being enabled, it could be the LS259 latch at M10/M11, or the LS06 at N9/N10.
If the enable is working, then the issue is somewhere in the sound circuit, and if you have replaced all of the parts (including Q6), check for cracked or broken traces, cracked resistors, and make sure all of the components are correct values per the schematics (as if someone else worked on it before you, people love to install incorrect parts sometimes). Also check R77, which is where the saucer sound connects to the output amplifier.
If it isn't being enabled, it could be the LS259 latch at M10/M11, or the LS06 at N9/N10.

