To the best of my abilities, I'm trying to repair an Atari 800XL which was sold as "non working unit". I found a new graphics chip and it's working ok. I though that, since I had it opened up, it wouldn't be a bad idea to replace the caps, even though they didn't show any leakage. So I did, i changed all of them but 3 are still remaining. They do not have any polarity marking and I eventually learn that they are Non-Polarized Electrolytic Capacitor. The marking reads:
"Nicon 4.7 uF, 35v, NP, -40 to +85ºC"
I'm trying to find replacement for these but I can't seem to find exactly the same and, since my knowledge on the topic is very limited (no formal education in electronics whatsoever) I would need some help.
The closest thing I found are capacitors with the same range of values but marked as "Bi-Polar" instead of "NP". I don't really know if it means the same as info I found in internet is contradictory.
If anything else fail, could I replace these capacitors with non-electrolytic ones? Again, since my lack of knowledge of non of them have polarity… all seems the same through my eyes…
Any help will be appreciated.
Best Answer
Several solutions
1) put two back to back series capacitors of 10uF/35V (negative with negative)
2) one polyester 4.7uF 40V like red WIMA (have similar small size)
3) buy a bipolar or NON polar electrolytic capacitor from a catalog distributor or better audio components or ebay. They are still selling them.