Heavily oxidized contact repair

[Ghudda]

So my friend unfortunately picked up a cart from a local game shop that isn't checking the condition of the games they're selling and I'm trying to clean it up for him.

As you can see, the contacts are pretty damn bad and an eraser and rubbing alc is only going to go so far. Could I use some sort of polishing tip with my dremel to clean it up or is there a better liquid solution I should be applying to the contacts with maybe some steel wool?






EDIT: Using basically the back of your typical store-bought sponge (scouring pad), i've been able to get rid of a lot of it.

[Hobie-wan]

Don't use a dremel, you'll eat the contact in a hurry. Steel wool and careful buffing just on the ones that need it might work. I've used a green scrubby kitchen sponge (just damp enough to be pliable) on really bad green contacts before. It saved some 2600 carts that probably lived in a garage for years. It's milder than sandpaper or other scraping which some people sometimes recommend for bad carts. Just go slow and keep checking every few strokes. It will still remove the gold layer too, which you want to avoid. Clean again with alcohol and an eraser after the scrubbing.

[Ghudda]

Don't use a dremel, you'll eat the contact in a hurry. Steel wool and careful buffing just on the ones that need it might work. I've used a green scrubby kitchen sponge (just damp enough to be pliable) on really bad green contacts before. It saved some 2600 carts that probably lived in a garage for years. It's milder than sandpaper or other scraping which some people sometimes recommend for bad carts. Just go slow and keep checking every few strokes. It will still remove the gold layer too, which you want to avoid. Clean again with alcohol and an eraser after the scrubbing.

Looks like I went way to rough on that contact, then.

Man, oxidation was just beginning to eat away at this board. Hopefully some of the traces aren't too corroded. Time to have a talk with the owner of the game shop about checking his products before buying/selling them. Also seeing a lot of bootlegs being sold without any sort of indication.

Should I bridge these corroded traces or should I seriously just return the cart if it's not worth it? I'm going to talk to the store regardless, but it'd be nice to fix the cart if I can.

Trace oxidation:

[Hobie-wan]

Yeah, ideally you don't want to expose the copper. That oxidises with the humidity in the air. That's the reason they're often gold plated, because that doesn't oxidise as easily. If you start seeing the gold fade away to silver, that's the point you're getting into damage territory. But yes, I just meant that kind of kitchen sponge.

I've often heard of people saying to 'tin' a contact, but solder is soft, so I'd be worried about it scraping little bits off with cart insertsion. It might be viable for stuff that doesn't get moved much, but I don't know about it being good for carts. Not sure what to say on protecting it at that point.

The good news is those 2 in the middle aren't connected to anything, so beyond not contaminating the system contacts, they're not needed for this particular cart to function.

[Hobie-wan]

That trace might need jumpering. Check for continuity from the contact to wherever it goes after jumping to the other side of the board.

[noiseredux]

I trust you already tried blowing on it?

[Ghudda]

That trace might need jumpering. Check for continuity from the contact to wherever it goes after jumping to the other side of the board.

jumping as in soldering a wire from point A to point B on the board (contact to point on the other side of board)?

I trust you already tried blowing on it?

[Ghudda]

That trace might need jumpering. Check for continuity from the contact to wherever it goes after jumping to the other side of the board.

Couldnt I just scrape down to copper on the trace and bridge past the corroded part via wire? Sorry I don't have a whole lot of experience with bridging/jumping traces so i'm not sure what the best method is in this case. My idea would be to scrape a bit down to copper on the trace above the contact and then run a wire to the back of the cart and connect it to the corresponding point on the back.

Enjoy my fantastic conceptual sketch I did in GIMP

[Hobie-wan]

If you can scrape and get the solder just to bridge the broken bits right there, sure. Might be kind of tight there though. A wire works too. As lone as you make an electrical path from the edge pin to wherever it is supposed to be going. If it's the leg of that chip, that works. If you can carefully scrape where it goes through the board and have enough room to solder there, it will work too. More wire obviously means more work to make it look nice, but some times a solid fix doesn't have to look nice.

[s8n]

I trust you already tried blowing on it?

lol


btw White Vinegar gets rid of corrosion i learned that off of Luke Morse , ive tried it on a WIImote bottom connector that i got for free. I could actually see it working as i dumped it in a pool of Vinegar after that i used a Fibreglass Pen then dumped the connector in Isopropyl Alcohol to clean any residue off.