any idea how to rescue this cartridge?

[september796]

this pokemon blue cartridge got wet in a wash machine several years ago. I never again got a sprite image out of it every time I tried it on my gameboy.
last year I cleaned the contact but couldn't get it working. then I discover interestingly enough that if I apply the cleaner and put the cartridge inmediatly on the gameboy it worked and could play for about 5 minutes until it crashed. I think it crashed because the cleaner dried in those minutes.
I use the same method and it works every time but then again.. until the cleaner dried. It's strange but I'm sure I can fix it.

those sections in red is where I use contact cleaner. you can see that those parts have something like white oxid that I can't get rid of. every time the cleaner dried up they come back. (that's why the game crashes after a couple of minutes I suppose)

as part of the cleaning process I got this funny glitchy sprite once LOL

I hope you understood my poor english and have some ideas to clean the white oxid or whatever it's called. Thank you!

 

[FAST6191]

It sounds like a reflow might be worth doing. Two main methods you would want to use if you can not identify the culprits.
1) Drag soldering. Hopefully that white oxide stuff as you deem it (it could well be lead oxide) has not interfered with the solder mask. I prefer a so called well tip iron for this but you can do it with a basic one if you practice a bit first. The idea being you drag a ball of solder across the pins and let it heat and reform the connections as you go (or put them down in the first place if you are soldering a new chip in) while the solder mask (the green top layer) stops it from sticking together. You might have to go back and drag it outwards (from the chip and away from the pins rather than along them) if solder bridges form, some might even do this first and skip drag soldering.
2) Hot air reflow. As it sounds you get a hot air station and then wave it over the chips to get the solder to melt and reform.

That chip on the right looks like some legs might not be aligned the best

There are more methods but they will require somewhat expensive equipment and achieve much the same results.

Alas I can not really eliminate what might be causing your problems -- it could be the ROM (the chip on the right), the MBC (the small square chip up high in the picture) or possibly even the SRAM (the Sharp chip), though without a battery there it is far more likely to be the other two.

 

[september796]

It sounds like a reflow might be worth doing. Two main methods you would want to use if you can not identify the culprits.
1) Drag soldering. Hopefully that white oxide stuff as you deem it (it could well be lead oxide) has not interfered with the solder mask. I prefer a so called well tip iron for this but you can do it with a basic one if you practice a bit first. The idea being you drag a ball of solder across the pins and let it heat and reform the connections as you go (or put them down in the first place if you are soldering a new chip in) while the solder mask (the green top layer) stops it from sticking together. You might have to go back and drag it outwards (from the chip and away from the pins rather than along them) if solder bridges form, some might even do this first and skip drag soldering.
2) Hot air reflow. As it sounds you get a hot air station and then wave it over the chips to get the solder to melt and reform.

That chip on the right looks like some legs might not be aligned the best

There are more methods but they will require somewhat expensive equipment and achieve much the same results.

Alas I can not really eliminate what might be causing your problems -- it could be the ROM (the chip on the right), the MBC (the small square chip up high in the picture) or possibly even the SRAM (the Sharp chip), though without a battery there it is far more likely to be the other two.

thank you for the advice I may try drag soldering first because it sounds harmless and easier using just soldering iron to reform the connections. I'm almost sure that the problem is just the oxide in the legs as I said the game runs OK if I clean especifically those parts and play right after but sadly it doesn't last too long until it's full of oxide again and crashes.
I could try hot air flow as well but I don't have a hot air station
The battery was dead so I took it off. I hope I can fix it, thank you again!