No sound

[Rao Palakodeti]

% I cleaned my dirty tapes with isopropyl alcohol, as somebody suggested, very lightly and dried them off right away. The only thing is used 77% alcohol. It cleaned the film but lost the sound. The magnetic strip is intact. Some film was not affected, but others were. What went wrong? It's an Elmo 1200 stereo projector. I think I ruined the film. The sound was there before cleaning, I checked.
Any help or ideas you can give are greatly appreciated.
Rao

[Joerg Polzfusz]

Hi!

I have not heard of magnetic recordings being ruined by Isopropyl. It’s normally only ruined by magnetic/electric fields etc..
I would suggest to check the film in a different projector. That’s because I guess that it’s the projector‘s fault: Most S8-films have been striped on both sides. And in many cases, (on digests etc.) the same mono sound was recorded on both tracks. (And of course, stereo recordings also needed both tracks - one for the left channel and one for right.) I guess that either your projector is broken or accidentally set to „mono sound from balance track only“ (or something like that).

[Dominique De Bast]

Hi!

I have not heard of magnetic recordings being ruined by Isopropyl. It’s normally only ruined by magnetic/electric fields etc..

I was thinking the same.

[Rao Palakodeti]

Thank you very much for the replies. I, too, thought the same. I have audio cassettes from 1972, but they never lost any sound.
Some films play the sound and others not. So, it is not the projection. Also, the film played the sound before I cleaned but not after. Let me check the mono and, stereo and balance controls to see if I accidentally moved any of them
Rao