New Guy Here Need Help -SOLVED!- identifying negative lead of these old Nichicon electrolytic caps.

These radial caps have no stripe or markings indicating which side the negative lead is.(or if they are marked I don't know how to read them) I see on the one side it says N P N which is indicative of transistors but I gotta go with my gut and say that these are no doubt electrolytic caps. They date to the late 70's. Does anyone know how to ID them? Thanks in advance. (for the cap in the middle marked C11)

 

Hello and thanks for the reply. I am aware of how to read caps that are striped like you stated. The problem is with the center cap in the pics. I took pics of both sides and there is no clear stripe on that particular cap. I can't read the cap marked C11 on the board.

 

Thank You very much Mr Dorke. So It would be a bad Idea to put in a replacement cap that had a dedicated polarity? I'm guessing that I should try to source a NP electrolytic for it's replacement.

 

Thanks again. This is for an old 16mm film projector sound amp. So your right on the money with it being for audio.