Hi,
I’m currently working on a Class of 1812 pin which makes a screeching sound when turned on. You can hear the music and call outs faintly in the background but the screeching plays constantly over the audio.
Anyone have ideas what the issue could be?
Here’s a list of jobs I’ve done so far:
1.Reflowed solder on pins
2.Tested voltages - 5v, 12v and -12v all good.
3. Replaced caps C8,C9,C18,C19,C36 andC37
4. Swapped the CO18 roms into a working A6 audio board and connected into CO1812 and everything works.
5. Connected the faulty A6 board into a Operation Thunder pin with the roms swapped and the same screeching issue happens.
6. Swapped out auxiliary power board with two known working boards. Issue still persists.
View attachment trim.E5FF607E-4A0B-4E40-A389-B829EB256C25.MOV
I’m currently working on a Class of 1812 pin which makes a screeching sound when turned on. You can hear the music and call outs faintly in the background but the screeching plays constantly over the audio.
Anyone have ideas what the issue could be?
Here’s a list of jobs I’ve done so far:
1.Reflowed solder on pins
2.Tested voltages - 5v, 12v and -12v all good.
3. Replaced caps C8,C9,C18,C19,C36 andC37
4. Swapped the CO18 roms into a working A6 audio board and connected into CO1812 and everything works.
5. Connected the faulty A6 board into a Operation Thunder pin with the roms swapped and the same screeching issue happens.
6. Swapped out auxiliary power board with two known working boards. Issue still persists.
View attachment trim.E5FF607E-4A0B-4E40-A389-B829EB256C25.MOV
Last edited: