There’s always another Super Nintendo around the corner. This time I’ve got an SNS-CPU-GPM-02 board on the bench for an electrolytic capacitor replacement, since they’re at that ripe age of olden times. It’s only a spare motherboard without a proper case, and it’s been doing some rather strange things, so I thought I’d give it a little attention.

I’d already removed the old surface-mount electrolytic capacitors and replaced the radial ones. One of the replacement radials was rated at 35 V rather than the original 25 V, because that’s what I had available and there was room for it. Of course, the replacement still needed the right capacitance, polarity and physical clearance. Some of these things sit beneath metal shielding, and there’s not much point installing a capacitor that prevents everything fitting together again!

While I was there, I also replaced the old 7805 voltage regulator and swapped the existing 2.5 A fuse for a 1.5 A Pico fuse. Those are the parts I used on this particular board, not necessarily a shopping list for every SNES revision. The idea was to give this troublesome motherboard another chance before considering more entertaining uses for it.

Best of all, I’d managed to get the old capacitors off without lifting any of the solder pads. Every single one survived! If you’ve ever worked on old circuit boards, you’ll appreciate how nice that is. The pads cleaned up reasonably well too, which was a relief after some of my previous adventures with surface-mount components.

The Hakko desoldering tweezers worked reasonably well on the smaller capacitors, particularly the 10 uF components, although I had more trouble with the larger ones. For installing the replacements, I found it easier to heat the solder pad and position the capacitor onto the molten solder before finishing the other connection. A little careful positioning was needed to keep the components from sitting crooked or hiding the remaining solder pad.

Unfortunately, I was still waiting for two 33 uF capacitors from element14. They were proving remarkably difficult to obtain, with repeated emails and promises about stock in the United States. It was beginning to feel like Groundhog Day! Eventually I called and discovered that they were apparently on their way, which was nice information to receive after all that chasing.

I also gave the board a bit of cleaning around the cartridge slot and refitted a rear connector that I’d previously borrowed for another Super Nintendo. The connector wasn’t sitting particularly straight afterwards, but this is a spare board without a case, so cosmetic perfection wasn’t exactly high on the list of priorities.

By the end of the recording, the components I actually had on hand were soldered in place. The soldering-iron tip wasn’t heating quite as evenly as I’d have liked, but the replacements were fitted and the pads still looked good. Those last two 33 uF capacitors were still missing, though, so the recap wasn’t completely finished and I couldn’t claim the original fault had been repaired.

If the board starts behaving itself after the remaining components arrive, excellent! If not, perhaps it’ll become a circuit-bending experiment instead. I’ve already got a Mega Drive 2 in mind for that sort of nonsense, so another Super Nintendo joining the party wouldn’t be the end of the world.