Game Boy Micro Not charging, I think it's the Diode, looking for help

[JohnnyPhantom]

I haven’t measured the area yet, but I did order the boards just in case. Figured I can remove the usb port on that charging board and just solder wires to the usb-c port mod I already added to the micro. Then will remove the resistors I soldered onto the usb-c mod board I installed, to sever that connection, and solder the charging board to where the resistors are now

 

[gangan]

I haven’t measured the area yet, but I did order the boards just in case. Figured I can remove the usb port on that charging board and just solder wires to the usb-c port mod I already added to the micro. Then will remove the resistors I soldered onto the usb-c mod board I installed, to sever that connection, and solder the charging board to where the resistors are now

I ordered like 6 of them. Figure they’re so small, may find uses for other projects. One thing to note though. Those boards do show they charge at 1 amp. I know some of the aftermarket batteries have overcharge circuitry built in so that may be fine. But just be weary of it. Charging them at 1 amp may be fine, but I think the default is around .5 amp. I’d keep an eye on the battery for a while just to be safe.

 

[mattek]

Hello guys,

I'd like to add two cents here.

Recently, a friend of mine, asked me to repair his GameBoy Micro which didn't charge. I checked all the fuses and EMI filters as suggested in this topic, but all of them showed continuity on my multimeter. Next step was tracing voltages according to @Ozito diagram (BTW: many thanks for that!) but to my amazement, voltages pre and post the 1 Ohm resistor were missing, not to mention those around the transistors.

I started searching for any useful information but couldn't find anything related to GameBoy Micro so I decided to extend my search to GBA SP and NDS. Here's the breakthrough: several times I came across information related to corroded traces located under the cartridge slot. With nothing to lose, I decided to desolder the cartridge slot on my console. Here's what I found:

One of the traces stopped conducting due to oxidation. Guess what? Mentioned trace leads directly to U2 Mitsumi Power Management IC which is responsible for battery charging. By using very thin wire and solder mask, I rebuilt corroded trace:

Without surprise, friend's GBM started charging the battery again.
In some places, the solder mask had also started to come off - I secured these areas too.

I hope this helps someone, as I found several threads on the web with similar problems left unresolved.

Ps: Stop blowing inside the cartridges!

 

[JohnnyPhantom]

Hello guys,

I'd like to add two cents here.

Recently, a friend of mine, asked me to repair his GameBoy Micro which didn't charge. I checked all the fuses and EMI filters as suggested in this topic, but all of them showed continuity on my multimeter. Next step was tracing voltages according to @Ozito diagram (BTW: many thanks for that!) but to my amazement, voltages pre and post the 1 Ohm resistor were missing, not to mention those around the transistors.

I started searching for any useful information but couldn't find anything related to GameBoy Micro so I decided to extend my search to GBA SP and NDS. Here's the breakthrough: several times I came across information related to corroded traces located under the cartridge slot. With nothing to lose, I decided to desolder the cartridge slot on my console. Here's what I found:

View attachment 422579

One of the traces stopped conducting due to oxidation. Guess what? Mentioned trace leads directly to U2 Mitsumi Power Management IC which is responsible for battery charging. By using very thin wire and solder mask, I rebuilt corroded trace:

View attachment 422580

View attachment 422581

Without surprise, friend's GBM started charging the battery again.

In some places the solder mask had also started to come off - I secured these areas too.

I hope this helps someone, as I found several threads on the web with similar problems left unresolved.

Ps: Stop blowing inside the cartridges!

That's great! I'll take mine off and look as well. Be interesting if that was it. I did cheat since my last post and I just found cheap cracked screen GBM so rather than putting more time on mine, I put it in a box, and shelved it, and installed the new screen I had ordered for it into the cheap parts one from eBay, It works great now, I'm still going to USB-C mod it, just haven't yet. But looks like its time to take that other one down from it's shelf and give this cart pin removal and inspection a look, got nothing to lose at this point as I have my "throw around, one to use" one already

 

[Ozito]

@mattek Great contribution, thank you for that. Also, very nice trace repair.
I mapped out where the vias seen next to the components where going to, a couple of months ago, but never posted the pics.
Anyways, hope this help someone.


color scheming changed just a bit, violet/blue is the same as cyan.

 

[ThaddeusShaw]

Think about the chance that the real problem might be deeper inside the board's power management system. Sometimes, the issue isn't with the parts we first think of. If replacing the charging board doesn't fix the charging issue, you may have to look more closely at the board's design. This means checking the schematics)of the board to find other spots that might be causing the charging problem.

 

[moon_rabbit]

Interestingly, as you can see in this video, the GBA SP is also affected by corrosion under the cartridge slot.
The problem is most often caused by blown fuses, missing parts, and corrosion.
Ps: Stop blowing inside the cartridges!