Replacing Nintendo NES electrolytics caps

Miscellaneous
1

So while doing a buncha work on my MB-SID and related projects, I figured I might as well work on breathing new life into my NES. It works fine (the cart connection could probably be replaced, but it’s not a huge problem) except that the video signal has waves and analog distortions on it. I’m using the RCA Video Out and have seen this both on new and old TVs.

After some lengthy research (Google hasn’t been very helpful), there were suggestions to replace some of the electrolytic caps. So, I busted out my NES and, sure enough, there’s a 2200uF cap by the RF section.

The problem is that the RF section is soldered to the mainboard in multiple places and has shielding sandwhiched in-between. I guess the FCC has crazy regulations regarding this sort of stuff, because it’s next to impossible to get to the top-side of the RF board without desoldering some rather large solder points. Question I have is - has anyone tried that before? I am able to get to the underside of the board, which means I can replace the 2200uF (it’s sticking out above the shielding that i can’t remove which is how I know it’s there), but I’m wondering if there might be other components to replace. Before I go desoldering the RF section, I thought I’d just check to see on the off-chance someone has done that before :slight_smile:

Either way, I’m going to go ahead and order new electrolytics for all the caps I find (there’s a few small ones on the mainboard) and will let people know the results!

2

So I finally had a chance to replace the caps - 4 total. 1 was the 2200uF cap in the power section and the other 3 were on the main-board. When I pulled out the 2200uF cap, I was able to spot some additional electrolytics, but I can’t get to them without figuring out how to take off the top shield of the power section (which is soldered to the mainboard). That said, after replacing the caps I did, there was a marked improvement. The wavy lines didn’t truly go away until I cleaned the 72 pin connector and associated header on the mainboard (along with cleaning the cartridge itself). It is likely that simply cleaning it might’ve fixed all my problems :slight_smile: I opted to try switching caps this time since the last time I cleaned it, the problem didn’t seem to go away.

Anyways, the Nintendo is working almost like new now, woot!