So my original Nintendo, that I got from a thrift store for like ten bucks, started having trouble reading games. This is a fairly well documented problem, so I decided to change out the 72 pin connector. It's not normally a big undertaking, and I wasn't even going to do a write-up for it, but about halfway through it got a little complicated and here we are. So read on and I'll run through it.
Like any 72 pin replacement, you start by removing the outer shell and shielding. It's not hard, just some phillips-head screws. After you get all that crap out of the way, you're left with this guy. I've always called it the 'kerchunker-chunker' but most people call it the cartridge ejector...
It is also held in by a few screws, but you have to kind-of pick up the board and slide it out. It's a little hard to wedge it out of there, but once it's out it looks like this:
The first thing I noticed was that discoloration on each of the corners... I slid the connector back a bit to have a closer look and you can see pretty well why it wasn't working. There's so much corrosion on those side pins, it's gonna take much more than just swapping out connectors.
Here's the same thing on the bottom side. It's not nearly as bad, but it's not good by any means...
I pulled the connector the rest of the way off to inspect the damage, and it's pretty rough:
Comparing the old (bottom) and new(top) connectors:
If you look closely in the corners, you can see how bad the corrosion is on these:
After I got the 72 pin connector out of the way, I could see how much damage had been done to the board. A few of the pins on both sides of the PCB had been eaten away entirely. Here' s a few shots of the damage up close:
In order to repair this, I had to find a way to make new pins. After quite a bit of research I found this stuff on Ebay. They were calling it 'solder glue', but its really just a conductive paint for doing PCB repair. After about a month of waiting for it to come from Hong Kong, I got 3 of these syringes.
I had no idea how far this stuff would go, but I didn't want to risk not having enough, considering it would take another month to get more...
The process is fairly simple, clean the crap out of the contacts (I use Windex and a good hard toothbrush), let it dry for as few hours, then use the needle point to apply as little paint as humanly possible and redraw the contacts. This stuff said it would take an hour to dry, but from my experience, its usually 3-4 hours so I leave it overnight. When it does eventually dry, it looks something like this:
Here's the bottom side redone:
Top opposite side:
And the main ones we had trouble with:
I actually re-did these after finding out the hard way they weren't dry... I wiped them off with an old rag and re-scrubbed it with the Windex/toothbrush. I didn't take a picture of the second try, but it was a lot flatter and it worked out nicely.
Anyway, after all of that dried out and I tested the continuity of every pin I started piecing it back together. Here's the new connector installed:
Initially, when I got the console put back together, it refused to boot. It kept giving me the flashing red light. After doing some research, I found out you can disable the anti-piracy chip rather easily, and in doing so correct this. (There's a really good write-up on it here:http://www.thevintagegamers.com/2013/06/bypassing-the-nes10-lockout-chip-mod-tutorial/)
So I did that and it still wouldn't work unless I pushed down on the cartridge really hard... After fiddling with it for a few days with the top off the console, Caytee suggested "Why not just leave off the kerchunker-chunker and just stick a book on it or something?" I sighed heavily and tried it to appease her. I wish I had thought to take a picture, because it totally worked...
This made me realize though, that the pins on the new adapter were already bent down too far, right out of the package... So I set to realigning the pins to make better contact, following this guide. My 72 pin connector has the grip of king kong and works every time!
A family favorite :)
Running in all 8-bits of it's glory:
My player 2 isn't very good at these games...
Like I said, I wouldn't have even done a write=up on this for a typical NES repair. It's usually just, realign and clean the pins. That usually does the job, if not a new 72 pin usually works.
Anyway, I hope you enjoyed the read. and I've got a TON of stuff on the bench I need to work on, so look out for more cool stuff soon!