Baofeng walkie talkie UV-16 PRO Mate not charging via usb type c.

[thesame]

I use to charge it via type c and It stopped charging , with the usb c connected i measure 5V on the pins that are going to the battery , and on the working one i can measure 9V on the pins, after opening it i found this sot23 smd marking ACA9E burnt, and i don't know what to replace it with. Some people say it can be SY8008CAAC wich is a Synchronous Step Down Regulator others say it could be voltage detector like XC6114B545MR.

[stj]

it's a 2 cell battery, so logically it's a boost convertor.
maybe next time,add a thermal pad to couple it to the metal shell

[thesame]

So how can i find the right part to replace it?

[stj]

not sure,
these codes are a pain in the ass to trace.
can you work out where the pins go?

[thesame]

I have removed the ic from the board so i can see the traces, with the ic on the board the small smd ( i think its a diode) under the usb port on the right it was shorted but after removing the ic its not shorted anymore. I have tryed to deliver 7v on the charging port since the walkie still works on battery and i have voltage on the diode and the capacitor under the burnt ic . I have also tested with the multimeters the pins from the ic conected to the type c port pins.

[thesame]

I have also opened the other walkie talkie and measured the voltages on the working ic with the type c connected, i have attached it here.

[stj]

thats a great picture, i can draw a schematic from that!
btw, do these radio's still have contacts on the back of the battery for a cradle like older radio's?

[thesame]

Yep the battery can be charged in the dock also it has external contacts too, but i'm interested in chargin it in the car where i have the usb cables available, thats why i bought them in the first place for the type c port.

[stj]

well the pinout of that boost convertor is:
1 - output
2 - OC
3 - gnd
4 - FB

6 - V-in
---

i didnt find a match yet, it's unusual.
most convertors use pin2 for ground.

[thesame]

You ment 5 . V-in , because it has only 5 pins ? I took another picture with the coil removed.

[stj]

thats contentious.
technically pin5 is missing,
some companies call the last pin pin5 others call it pin6

[R_J]

FAN2500SX, has those markings I also see PAM3103 (ACAyw) but different pinout
None show an inductor as part of the circuit.

[Agent24]

Thought I had it with the XC6367 from Torex, but the pinout is all wrong. And it uses an external transistor anyway.

Annoying when you don't know which part of the code is part number and which is lot/factory/date etc code.

If you can get your hands on (or PCB photos of) another radio the same model but different year production it may help

[stj]

it's a new-ish model though.

[CapLeaker]

FAN2500SX, has those markings I also see PAM3103 (ACAyw) but different pinout
None show an inductor as part of the circuit.

Found that too… but that doesn’t help either, lol.

[Agent24]

it's a new-ish model though.

I guess it's a new chip too that nobody's heard of yet.
I wonder if trawling through DC-DC converters on LCSC or something would help...

Why don't they just use a MC34063 if all it's doing is charging a battery not like efficiency matters in that scenario.

Has anyone tried asking Baofeng what chip they used? Probably they'll ignore you but who knows, maybe they'd be helpful. Lol.

[thesame]

I have tryed to contact them vi aliexpress where i bought them to ask about a schematic or a service manual , but sadly no one is answering the chat.