MV-4F and cart connections

I’ve owned a MVS-4-25 for a while now but never took the time to really learn how to clean it up inside. I got it in, I think, pretty great shape. However, I do have problems with some cart/slot combinations. Some games work fine in some slots and are a huge pain to get to work in other slots. I’ll either have to try reseating the cart, not seating it solidly all the way down, leaning it forward/backward slightly, etc all in an effort to get that sweet spot of a perfect connection.

I’d like to learn more about the hardware I’ve got and what I can do to improve, restore, and maintain it. With respect to the connection issues I’ve got, what can be done? I recently saw someone selling aftermarket replacement cart slots. It’d require a ton of unsoldering/soldering, but would it be worth it? Is there a better alternative? Is it just a matter of cleaning the carts and slots? I saw someone else selling a slot-cleaning kit. Maybe that’d help?

Anyone have any experience dealing with this issue? What would you recommend?

Thanks for the help!

Edit: Should have done more googling before I posted. I've found some good posts about cleaning cart slots. I'd still like to hear people's experiences replacing the cart slots, though!

Cart slot replacement is too drastic and should only be done as a last resort when a slot isn't good at all anymore. Definitely clean the slots well. Know that certain cart/slot combinations may always be temperamental, and this is normal to some degree.

That’s not uncommon. It even happens on AES. My Fatal Fury Special always gives me hell and I’ve cleaned it like crazy. I swear the boards are a mm or two thinner than they should be.

Check for bent pins on the slots giving you hell. Cut a white t-shirt and soak it in isopropyl, then wrap it around a credit card (flat one if you have it, not with raised letters) and plunge it in and out of the slot. You’d be surprised how dirty “clean” looking pins and cart slots are once you clean them.

Same with the carts themselves. Clean the contacts

Or even better, get a can of Deoxit D5.

Regarding Deoxit, should it be used in place of the alcohol, or in addition to?

deoxit will do a better job then alcohol, but alcohol is usually good enough.

The instructions on my DeoxIt mention applying Gold/Shield/Grease after the initial cleaning. Do any of you have any thoughts on using these on our MVS cart slots?

Only use the Deoxit.