Capacitor Discusion

[Keith Courage]

I was wondering what everyone here thought about certain brands of capacitors and or any bad stories had with cheap capacitors before.
Also, are cheap generic capacitors really so bad? I always use name brand stuff when I do repairs for other people but I did use some cheap Chinese ones on a spare DUO I have that I never plan to get rid of(sentimental reasons). I figure if the caps go bad I can just change them again. It's been 3 years since and the DUO still works great.


 

[ApolloBoy]

You might be OK getting away with cheapo Chinese stuff but I'd highly recommend using stuff like Nichicon and Nippon Chemi-Con. I used to use Chinese caps from eBay but now I just get name-brand caps since they'll probably last much longer.

[thesteve]

the life of a cap is defined by its chem compounds, construction and power density
a cap that will be taking more ripple current will need either a higher boiling point (temperature) or higher voltage rating (larger).
I have no issue with Chinese capacitors in ceramics and common electrolytics.
tant caps are only available from a few MFG's and are all considered high end.

[BlueBMW]

I think Ive typically gone with Panasonic caps... mostly because Im accustomed to their part number system now hehe.

[Freezer]

I'm in the process of completely recapping my first TG16 right now.  But I've repaired a dozen or more flat panel monitors/TVs as well as 2 Sega Genesis's.  There definitely is a difference in capacitor quality, but the quality also depends on the application.  Monitors and TVs seem to stress capacitors far more than old school video game consoles.  As such, capacitor failure is much higher in monitors and TVs.  The brands I've heard great things about are Panasonic (the brand I always use), Nichicon, and United Chemi-con.  Of course, within any given manufacture are multiple "series" and knowing the correct series to use makes a big difference as well.

For Panasonic, my preference is FM, then FC, then M, and lastly FR.  FM and FC are very similar, FM has better specs and is typically cheaper, but not always available.  The other series I'll only use if neither FM or FC are available.  As a general rule to capacitors you want a low equivalent series resistance (ESR) value, which the FM and FC have.  The job of a capacitor is to hold a small charge, and then release that charge when the voltage drops.  How freely the capacitor releases this charge is the ESR value.  As capacitors age and dry out, they tend to hold onto this charge and resist giving it up.  Thus older (and crappy caps to begin with) will have a higher ESR value.  ESR is the most accurate measure of how good or bad a capacitor is.  Unfortunately, very few multimeters can measure ESR.  You typically need a special ESR meter - I have the Blue ESR meter (http://www.anatekcorp.com/blueesr.htm).

Bringing this discussion back to retro video games.  As I recapped the TG16 I measured the ESR of the original caps as well as the new caps.  The caps I took out all had higher ESR values, but none of them were so high that the capacitor would be considered "bad."  In a week or two I'm going to post pictures of my recap job and I'll include ESR values before and after the recap.

One of the big exceptions to the rule about low ESR being the best is audio capacitor use.  There's a whole special class of capacitors for audio use.  I believe one of the most respected names is Elna.  Obviously, video game consoles audio in them, so if recapping them do you need to account for that?  Well a lot of people out there have tested general purpose caps in audio applications.  Most people agree that the Panasonic FC and FM caps are the best general purpose caps for audio applications.  So if you stick with Panasonic FC/FM then you should be good to go.

[turbokon]

I've always ordered thru holes nichicon caps. I tried the smd ones that's used on the turbo duo and express but they are a pain to solder on. I see peeps are also using the smt square/rectangular kinds. Looks to be easier to solder on. How hard is it to get the right physically size so they could be placed on the original pads?

[thesteve]

a lower ESR cap will produce less loss (heat) as the voltage is changed across it.
often a cap is used for signal coupling, where you want the cap to be large enough that the voltage across it doesnt change and the ripple (signal) passes through instead.
A lower ESR cap can have higher surge currents, but may experiance excessive surge.
the lowest ESR are typically silver/tantalum and ceramic.
aluminum can be low of moderate ESR.
wet tantalum is typically high ESR, but are used because of their extreame reliability.

[ProfessorProfessorson]

Just for the sake of linking to it:
http://www.pcenginefx.com/forums/index.php?topic=11068.0