Hardware No fan or joycon charging when docked/connected to 15V charger

[arar]

Hi! I've been chasing this issue for a few days now where my Switch v1 won't charge the joycons and spin up the fan when it's connected to a 15V charger or docked which results with it overheating on the dock. This issue doesn't occur when I use a 5V charger.

I've already changed M92 for a known good one and checked around MAX8969 area (AJZ chip) where voltage for the fan and joycons comes from. I figured out that when I connect a 15V charger (original Nintendo one) this chip doesn't get an EN signal (1.8V) which means something on the board isn't telling it to turn on.

By looking at the PCB scans available online I traced EN signal to two places. First being the component marked 42 nearby the dual mosfet (PP5) where the output of 8969 is connected and the second being the CPU. I think this signal originates from the CPU and firmware since this 42 IC is connected to the gate of the dual mosfet. I might be wrong here, but it seems like it's there to let the output of 8969 through when EN is present.

Now, here comes the interesting part. Since my switch is moddable I booted up Linux and fan works there without any issues on a 15V charger. Joycon charging still doesn't work there but I think it's not supported. So I rebuild my eMMC with a fresh OS guessing it's the firmware at fault but it didn't solve this.

I've come to this point with the help of TronicsFix forum users and that's where the original thread is, but I decided to start a new one here to maybe reach someone who had this weird issue before. I'm really out of ideas at this point.

Thanks!

 

[Lamcza]

hello there. I am a noob so I will totally write something here.

it doesn't charge joycons and spin fans and it will do the same just on charger without the joycons? also if you have moded switch any of the temps are raising while fan starts spining?

I remember that I saw something like this somewhere hmmm

yeah it might be here

 

[arar]

hello there. I am a noob so I will totally write something here.

it doesn't charge joycons and spin fans and it will do the same just on charger without the joycons? also if you have moded switch any of the temps are raising while fan starts spining?

I remember that I saw something like this somewhere hmmm

yeah it might be here

It spins the fan without the charger fine, but after I plug in a 15V charger fan is completely dead (which doesn't happen with a 5V phone charger). Same with joycon charging, they charge when I connect a 5V charger, but don't when I use a 15V charger.

 

[Lamcza]

It spins the fan without the charger fine, but after I plug in a 15V charger fan is completely dead (which doesn't happen with a 5V phone charger). Same with joycon charging, they charge when I connect a 5V charger, but don't when I use a 15V charger.

so if fan is dead on 15v charger this is probably why joycons are not charging that's fan seems fishy to me now : p or it can be something before fan but am not a board wizard 🪄






sorry but I don't have 50 min to watch the vid now but it might be useful symptoms are similar enough :x


this is also interesting
https://repair.wiki/w/Nintendo_Switch_No_Fan_Spin_Voltage_Injection_Method

 

[arar]

so if fan is dead on 15v charger this is probably why joycons are not charging that's fan seems fishy to me now : p or it can be something before fan but am not a board wizard 🪄

I was also testing all the stuff I did with just a battery plugged into the board outside the housing and EN signal on 8969 didn't appear on a 15V charger, but did on a 5V one. So exactly the same fault without the fan plugged in.

 

[Lamcza]

I was also testing all the stuff I did with just a battery plugged into the board outside the housing and EN signal on 8969 didn't appear on a 15V charger, but did on a 5V one. So exactly the same fault without the fan plugged in.

I don't think it can even work without the fan if there is so much connection between fan-joycons because of power rail? : D ok my noob expertises ends here w8 for some real 🪄 good luck