Nice to see this forum is still kicking! Whats up nightwolve, been a LONG TIME
Hey there! Uh, did I know you by another alias? override doesn't ring a bell.
Hence why AC non-polarized ceramics are better. Gotcha. Well, I had a bad experience when I switched to all ceramic with my SNES, so now I'm paranoid about going that route. Blew $11 bucks and then I switched back to cheap electrolytic anyway....
I thought I'd mention an update while I'm at it with regards to this. I believe I figured out the problem when it comes to replacing standard aluminum caps with high-capacitance ceramic equivalents. First off,
I highly recommend that everyone purchase a Digital Multi-Meter that can measure capacitance for cap replacement jobs. Very important I think! I'm extremely happy with the
Vicky VC99 I recently purchased that can measure caps as small as 40nF.
OK, so anyhow, here's why it's important to have this feature: every cap in your kit has a different value than what is stated, ceramics are usually a lot lower and aluminums are usually somewhat higher. If it's a 100uF cap, if might actually read 120uF or 95uF, all varies. So before you replace a cap with a new one, you can test each one with a good DMM (if you get one) and pick out the best from the lot that you bought! Not all are created equal, etc.
Now, here's the deal with what happened with my SNES. I bought 2.2uF, 10uF and 100uF in ceramic. Expensive, but hopefully lifelong and would never leak, so cool deal right? Well, after doing a full replacement, it looked like everything was working fine, but when I tried Super Street Fighter II, when Ryu does his opening fireball and the screen goes *full* white and bright, the TV would lose sync and right before at the top, it'd look like say what electricity would, etc. I played around using a resistor in between the Luma output which would fix it, but you'd lose the perfect contrast that the SNES outputs because the thing has a rock-solid Luma to begin with and doesn't need to be messed with... Not an acceptable solution.
Anyway, I finally got sick of this, and I declared all of these high-value ceramic caps a big mistake, and I had paranoia in ever using them again. So I put new aluminum caps back in place and everything worked fine again! However, after my new VC99 DMM arrived, I tested all of the ceramic caps that Digikey had sold me (I blew $11 bucks after all!). Here were the results: the single 2.2uF cap came out to 3uF, the 10uF caps were 9.3uF - 9.5uF,
BUT, the 100uF caps were like 64uF!!!! They were
off by f*cking 40% from the stated value, WAY unacceptable and those were the caps that caused the problem! The Luma/Y amplifier circuit on 1st generation SNES systems has a 200uF cap before going to the Multi-AV out to kill off the remaining 1.35 Voltage. 2 100uF caps are connected in parallel for this. Anyhow, as a result, I put the small 2.2uF and 10uF ceramic caps back on the system and I left the 100uF caps in aluminum...
So, ProTip: Stay away from high-value ceramics (above 10uF) or get a DMM that can measure them for you so you don't get f*cked by one that's way way too low from the stated value!!!
The other thing: Digikey sent me a notice that TDK discontinued manufacture of most of the caps that I had bought from them for this SNES job... (I was like, thanks a lot, a$$holes!) So yeah, my experience may not be reflected by anyone else and any general rules may not apply. Nonetheless, I don't trust a new cap now unless I can pre-measure it before soldering it on and I wanna be able to pick out the best ones first out of the package... The
Vicky VC99 allows for this, get it! Then throw another dollar to
this Chinese seller for the alligator clips, so you can clip on the leads to a cap for easy testing, and you're all set (it doesn't come with them).
* Discontinued ceramic cap in question (100uF 6.3V):
http://www.digikey.com/product-search/en?x=17&y=14&lang=en&site=us&KeyWords=445-4827-NDTDK's stated reasons:
http://media.digikey.com/pdf/PCNs/TDK/Dipped_Y5V_Disc.pdfI bought 4 of those f*ckers, and they were ~60-70uF, VERY far off! The aluminums are usually higher than the stated value is what I am finding with my cap measuring DMM.