Gaming GBA SP Will not charge even with new battery

[WirelessFidelity]

Hello,

I got a GBA SP the other day from Goodwill. I tried to charge it, but it flashes the charging light on then off. I wired up a dummy battery and managed to power it that way, and it worked fine then. However, I believe I accidentally shorted out the terminals and blew a fuse. The system then would not turn on. So I took the system apart and bridged both fuses with blobs of solder. It still would not charge. I then bought a brand new battery to test it with. The system turns on and plays fine, but it will not charge. The charge light goes on then off. The charge port seems fine, and I brushed it with isopropyl alcohol just to check. I believe the port is not the problem since the light comes on momentarily when I plug it in. I've tried it with 2 different chargers and the light goes on then off with both. How can I fix this? Thanks in advance


EDIT: Added pics of the PCB

 

[FAST6191]

While I looks OK on that image (most of the ones I have seen in the past look to have a fractured corner) the next step is the EM8 choke

https://gbatemp.net/threads/gba-em8-component-missing-solution.540092/

The battery contact with the writing on it also looks a bit corroded, though I suppose it would not power on at all if it was that far gone..

 

[WirelessFidelity]

Firstly, thanks for your help. I just checked the EM8 with my multimeter and I got continuity on both sides. What should I check next?

 

[FAST6191]

What resistance? Continuity mode could be seeing something still but the resistance would still be too much. You could also try bypassing it -- it is mostly a noise thing so a test should not bother it if you have a reasonable supply.

After that I am not sure really. Fuses, battery connections, connector issues and EM8 sort or are responsible for most of what we see and I don't have a proper diagram of the charging system to go properly in depth.

 

[WirelessFidelity]

What resistance? Continuity mode could be seeing something still but the resistance would still be too much. You could also try bypassing it -- it is mostly a noise thing so a test should not bother it if you have a reasonable supply.


After that I am not sure really. Fuses, battery connections, connector issues and EM8 sort or are responsible for most of what we see and I don't have a proper diagram of the charging system to go properly in depth.

It was 000 continuity, so zero resistance. I don't quite know where to go now. Maybe I could try scrubbing the board with isopropyl alcohol? There is some residue on it in places.

 

[FAST6191]

Residue is not likely to short anything and prevent it from charging. That said while you might have tested the component that means little if it is not connected to the board -- if you want to reflow the solder on the legs of it then that will allay some worries here.

Between the fuses (rare on the GBA, common on the DS), deep discharge battery/cheapo Chinese battery and the EM8 thing that has solved most charging issues that are not massive port damage* or other massive motherboard damage. I don't have a working diagram of the PCB or the charge circuit as a more conceptual thing at this point. You can start following it through looking for broken traces but that is getting desperate.

*if the leg on that battery charger is as bad as I think then I also don't know about the port. You might clean that.

You can come the other way if you want and wire in something directly to the battery to charge it directly (if you are buying Lithium chargers do check the voltage as .1V difference on the named voltage can mean a slightly different style of charger is needed -- the GBA SP would have been among the first consumer devices so it likely will be the older type), might even be able to get one of those wireless chargers for it. Alternatively you could probably fly a wire from the port (maybe with suitable resistor) to the battery terminals and bypass the internal stuff, not ideal but better than nothing. Do the reflow thing first though.

 

[bibliomon]

Hey there, I would like to ask, how would you bypass/bridge the EM8 with the four contact points? Just put a blob of solder there?

Residue is not likely to short anything and prevent it from charging. That said while you might have tested the component that means little if it is not connected to the board -- if you want to reflow the solder on the legs of it then that will allay some worries here.


Between the fuses (rare on the GBA, common on the DS), deep discharge battery/cheapo Chinese battery and the EM8 thing that has solved most charging issues that are not massive port damage* or other massive motherboard damage. I don't have a working diagram of the PCB or the charge circuit as a more conceptual thing at this point. You can start following it through looking for broken traces but that is getting desperate.

*if the leg on that battery charger is as bad as I think then I also don't know about the port. You might clean that.

You can come the other way if you want and wire in something directly to the battery to charge it directly (if you are buying Lithium chargers do check the voltage as .1V difference on the named voltage can mean a slightly different style of charger is needed -- the GBA SP would have been among the first consumer devices so it likely will be the older type), might even be able to get one of those wireless chargers for it. Alternatively you could probably fly a wire from the port (maybe with suitable resistor) to the battery terminals and bypass the internal stuff, not ideal but better than nothing. Do the reflow thing first though.

 

[FAST6191]

Hey there, I would like to ask, how would you bypass/bridge the EM8 with the four contact points? Just put a blob of solder there?

Probably not.

If you have a DS motherboard you can grab em10 from then do that.

Otherwise I will need to pin mine out to figure out what goes.
4 pin chokes have 4 pins for a reason -- https://www.coilcraft.com/cmc/index.cfm . All the pads will be connected to another but not all at the same time (2 pins will be connected and so the other 2 to each other) but I don't know offhand what the arrangement is (you have two main options as I doubt it is diagonal, if two of the pins are still connected then you have your answer. Also it is really not great to be bypassing such things as a long term option -- testing with a clean source is fine but go back to a noisy thing like the GBA era adapters and it is not ideal at all.

As far as the actual procedure. You might be able to get a blob to go between the pins, personally though I would get a small length of wire and use that.