Hi guys, some time no see.
I am a proud owner of a whirlwind (system 11b).
While attempting what I would call a trivial repair (PSU connection replacement with molex) I made a terrible mistake: I connected all the tensions backward (please, don’t ask).
As soon as I juiced the boards, U18 and U17 made fireworks.
I felt like loosing my best friend in a misadventure.
After a night passed trying to recover all my self-confidence, the day after I went to check the damage extent (after connecting the tension in the right order). Having noticed that some IC was blown in the audio board, I removed it and lit the game. To my surprise, the game was still booting fine and I could play a game from the start to the end. You cannot imagine (yes, you can really) how lifted I felt.
I then ordered new 1458 opamps, replaced U18 and U17 and fired everything up again: I had speech! But I could not hear the main theme. Replacing audio ROMs (U4, U19, U20, U21, U22) with fresh ROMs (I have an eprom burner) made no difference, nor replacing U26 and 27 (main program roms).
After some game-testing I noticed that:
- I have speech, but not all the speech (i.e. the cellar old man is missing)
- I have sound FX, but not all sound FX (i.e. the outlain sound is missing, the cellar expulsion sound is missing, the right ramp sound is missing)
- I have some music, but not all music (main theme is missing).
I made the sound test and I have the wrong tracks selected while selecting the “files”: main theme is the “waiting for ball launch theme” etc. I will upload a video on youtube, just in case.
A friend of mine will soon give me a bad cats audio board for testing, so it will be possibile to understand if the issue is there or in the cpu board.
Now, the 1000 dollars question: what could be the cause of my (very donkey-me specific) sound issues?
Thanks in advance for the help!