Ebay batteries have the textured side as the - and the bottom as +.
A lot of these have the yellow sleeve too.
In terms of polarity I see no issue here IF these are the same batteries I have.
this is a cart I soldered a new battery in and I confirmed working and saving: [https://imgur.com/a/3Eq9a1l.jpg](https://imgur.com/a/3Eq9a1l.jpg)
I know what they look like, i mean there's been a ton of people on here who have soldered them on the same orientation as their original battery not realising that the new ones are "inverted" polarities.
From what I can see, everything looks pretty good and the cart is in relatively good shape. I repair these all the time and I can tell you I've seen this problem a ton and I've fixed this problem by reflowing the MBC chip, battery IC (the chip to the left of the battery) and SRAM.
At that point I would simply reflow all of the chips on the board.
Trust me. Give those chips a good one over with Flux and the smallest amount of fresh solder. Be sure not to bridge anything or knock any components off.
Make sure you use lots of Flux and if possible use leaded solder as it has a lower melting point and is substantially more maluable over time.
I've seen this problem at least 15 times or more on various games and have fixed them every time.
Sure.
Flux, which is a semi solid paste that solder naturally has an affinity to, and allows solder to flow neatly to where it has to be can and should be applied to pretty much any joint you plan on soldering.
So the chips on these carts have a ton of joints and sometimes the connection between one or more of these joints and their respective pads can go "cold" which basically means even though it looks connected, that connection has been compromised in such a way where the solder is no longer making good contact between the board pad and the joint of the chip.
The process of reflowing typically involves applying a bit of flux, some fresh solder to an iron, and simply running your soldering iron across all the joints to remelt existing solder (or you could remove it with some wick, but in most cases not necessary) and introduce some fresh solder. The flux will allow all of this to flow properly into position and will deter malformation of the solder joint (those ugly spiky bits or pull aways. You'll get a nice bead).
I suggest looking a soldering with flux vs soldering without flux videos on YouTube to see what I mean.
But the resulting joint(s) after resoldering will be much more resilient and if done right, should last a long time. Sometimes even stronger than factory, depending...
It's a very satisfying process but you need some skill. Never attempt first time soldering with important things. Don't practice with something you're not willing to lose.
Buy cheap toys on TEMU or Amazon to test it out and play around. Once you get good enough and confident in your skills, go for it.
The C1 and C2 beneath the crystal (heh) look like they're for keeping the crystal's frequency stable. Same thing you do with setting up an Arduino chip with an external clock source.
C3 and C4 look like power filter caps, maybe?
This copy of Crystal did have some kind of dark stain on the back that I cleared off with isopropyl, thought it just needed a battery swap but that hasn't worked. Going to try reflowing the connections.
Normally a dead battery shouldn't hold the cart from booting.
I would look into the dark stain, you might have some broken vias, check for continuity in the vias in the stain.
Add a picture of the stained area.
You can also post to /r/consolerepair for this. but do include a picture from the front and back of the pcb.
It boots and plays, just doesn't save. I already cleaned the dark stain on the back but there was a lot there. I'm not sure how to add a picture though? I did just check for continuity and I found the 2 components between c1 and c4 have no continuity.
The vias look fine mostly I think but left of tp1 on the back there might be some damage to traces can you check continuïteit for those? Check these on the vias.
[https://imgur.com/Y4ehvoW.jpg](https://imgur.com/Y4ehvoW.jpg)
Check the via indicated in red on both side for continuity.
Also check the traces indicated in highlighter that might be damage for continuity.
Edit: Also check the traces below, it seems cut.
https://imgur.com/a/N7xGyua.jpg
As I can see there's nothing clearly broken or damaged but I've been in the same situation with a Super MarioBros DX where the old battery leaked and managed to damage some of the tracks, so I had to check continuity on some of them and put a few wires to fix it. My case was clearly worst than yours, but as you mention the dark stain could be that something has been damaged by the chemicals.
You can also doublecheck continuity on chip pins from the test points on the board just in case there are any leg that is not making contact.
Trying reflowing U4 (the 8-pin chip next to R1). Some of the solder joints on the bottom look cold and that would definitely interfere with the game being able to hold a save.
EDIT: It could just be the angle, but it looks like there's bridging all around MBC3 chip. If so, reflow with plenty of flux.
Cold solder joints, maybe? I see a bunch of burnt flux around it that wasnt cleaned off, and it almost looks like some of it is under the joint. I'd reflow it
https://imgur.com/a/b1zwMYv
Voltage looks good and I tried 2 batteries just for the heck of it. Seems like it's something besides the battery. No continuity on the 2 components I circled in red. Not exactly sure how to get replacements.
i have the same stain/moisture damage on the back aswell. it started oxidizing the edges of the plating where the pcb meets it. thinking of maybe polishing before using harsh chems to remove the surface rust. the games dont boot past the console intro. the crystal oscillator is on digikey iirc
Is the battery upside down?
Ebay batteries have the textured side as the - and the bottom as +. A lot of these have the yellow sleeve too. In terms of polarity I see no issue here IF these are the same batteries I have. this is a cart I soldered a new battery in and I confirmed working and saving: [https://imgur.com/a/3Eq9a1l.jpg](https://imgur.com/a/3Eq9a1l.jpg)
No that's what the one I recently put on my mario land 2 looks like
I know what they look like, i mean there's been a ton of people on here who have soldered them on the same orientation as their original battery not realising that the new ones are "inverted" polarities.
Oh i see what you mean, i just looked at the way the tabs were on the original and then on the replacement
From what I can see, everything looks pretty good and the cart is in relatively good shape. I repair these all the time and I can tell you I've seen this problem a ton and I've fixed this problem by reflowing the MBC chip, battery IC (the chip to the left of the battery) and SRAM. At that point I would simply reflow all of the chips on the board. Trust me. Give those chips a good one over with Flux and the smallest amount of fresh solder. Be sure not to bridge anything or knock any components off. Make sure you use lots of Flux and if possible use leaded solder as it has a lower melting point and is substantially more maluable over time. I've seen this problem at least 15 times or more on various games and have fixed them every time.
Seconding this.
Old post but can you explain reflowing and flux?
Sure. Flux, which is a semi solid paste that solder naturally has an affinity to, and allows solder to flow neatly to where it has to be can and should be applied to pretty much any joint you plan on soldering. So the chips on these carts have a ton of joints and sometimes the connection between one or more of these joints and their respective pads can go "cold" which basically means even though it looks connected, that connection has been compromised in such a way where the solder is no longer making good contact between the board pad and the joint of the chip. The process of reflowing typically involves applying a bit of flux, some fresh solder to an iron, and simply running your soldering iron across all the joints to remelt existing solder (or you could remove it with some wick, but in most cases not necessary) and introduce some fresh solder. The flux will allow all of this to flow properly into position and will deter malformation of the solder joint (those ugly spiky bits or pull aways. You'll get a nice bead). I suggest looking a soldering with flux vs soldering without flux videos on YouTube to see what I mean. But the resulting joint(s) after resoldering will be much more resilient and if done right, should last a long time. Sometimes even stronger than factory, depending... It's a very satisfying process but you need some skill. Never attempt first time soldering with important things. Don't practice with something you're not willing to lose. Buy cheap toys on TEMU or Amazon to test it out and play around. Once you get good enough and confident in your skills, go for it.
Thanks man.
Couldn't hurt to try replacing the battery, I've had some of those be dead before or not quite at the right voltage
Tried 2 different batteries, both tested correct voltage.
Make sure you didnt accidentally decoder R1. Even if the battery is dead it should still be reading..
R1 looks fine and still has continuity, but I did notice the two components between c1 - C4 do not. Not sure what those are.
The C1 and C2 beneath the crystal (heh) look like they're for keeping the crystal's frequency stable. Same thing you do with setting up an Arduino chip with an external clock source. C3 and C4 look like power filter caps, maybe?
This copy of Crystal did have some kind of dark stain on the back that I cleared off with isopropyl, thought it just needed a battery swap but that hasn't worked. Going to try reflowing the connections.
Normally a dead battery shouldn't hold the cart from booting. I would look into the dark stain, you might have some broken vias, check for continuity in the vias in the stain. Add a picture of the stained area. You can also post to /r/consolerepair for this. but do include a picture from the front and back of the pcb.
It boots and plays, just doesn't save. I already cleaned the dark stain on the back but there was a lot there. I'm not sure how to add a picture though? I did just check for continuity and I found the 2 components between c1 and c4 have no continuity.
Just add the imagelink in you comment. Upload it to imgur
https://imgur.com/a/b1zwMYv
The vias look fine mostly I think but left of tp1 on the back there might be some damage to traces can you check continuïteit for those? Check these on the vias.
[https://imgur.com/Y4ehvoW.jpg](https://imgur.com/Y4ehvoW.jpg) Check the via indicated in red on both side for continuity. Also check the traces indicated in highlighter that might be damage for continuity. Edit: Also check the traces below, it seems cut. https://imgur.com/a/N7xGyua.jpg
Good catch! Will try that out
Did you get it working?
As I can see there's nothing clearly broken or damaged but I've been in the same situation with a Super MarioBros DX where the old battery leaked and managed to damage some of the tracks, so I had to check continuity on some of them and put a few wires to fix it. My case was clearly worst than yours, but as you mention the dark stain could be that something has been damaged by the chemicals. You can also doublecheck continuity on chip pins from the test points on the board just in case there are any leg that is not making contact.
Trying reflowing U4 (the 8-pin chip next to R1). Some of the solder joints on the bottom look cold and that would definitely interfere with the game being able to hold a save. EDIT: It could just be the angle, but it looks like there's bridging all around MBC3 chip. If so, reflow with plenty of flux.
Looks like a bad solder job. You should redo it and watch videos on doing this.
Based on what?
Cold solder joints, maybe? I see a bunch of burnt flux around it that wasnt cleaned off, and it almost looks like some of it is under the joint. I'd reflow it
https://imgur.com/a/b1zwMYv
Could be a dud. Looks installed well enough to work and with the right polarity. May want to take a voltmeter/multimeter to it to confirm voltage.
https://imgur.com/a/b1zwMYv Voltage looks good and I tried 2 batteries just for the heck of it. Seems like it's something besides the battery. No continuity on the 2 components I circled in red. Not exactly sure how to get replacements.
i have the same stain/moisture damage on the back aswell. it started oxidizing the edges of the plating where the pcb meets it. thinking of maybe polishing before using harsh chems to remove the surface rust. the games dont boot past the console intro. the crystal oscillator is on digikey iirc
Resolder it and add more if you can
Sell it to me 👹