Before I continue please note this board is the HAC-CPU-21 board, yet it’s unpatched. It’s not meant to be patched based on both the serial number and the fact it was manufactured in 2019. It’s possibly even a V2 better battery SoC, under the normal XAJ serial number, but I have no way to prove this that I know of, just most HAC-CPU-21 boards are patched V2s.
I recently installed a certain X86 board and sometime after installation charging stopped working.
I took out the X86, removed all wires, solder I placed, e.t.c and it still does not charge.
Battery is definitely good. It was charged before installation.
I may have been too liberal with my application of IPA. Possibly turning on power before the IPA evaporated fully, possibly making shorts.
I tried with 3x different USB-C cables. One of which is the official charge which I tested on another Switch and works as expected.
During installation and uninstallation I never had it turned on, except maybe possibly once. I also made sure there was no shorts/bridges.
Injecting a payload through RCM works, e.g., TegraRCMSmash and a hardware injector device. Yet actually charging does not. Hekate’s mA meter does not make a meaningful difference when a cable is connected, it stays around -450 or -500. Hekate’s USB PD info does not detect a USB connected AT ALL.
I tested at 2K ohms range with my multimeter around a few of the larger caps and resistors and these are my results. There may be more resistors or caps I haven’t tested. But generally speaking, I’ve tested the majority of the gray/brown caps.
Picture of the caps I’ve tested that show weirdness:
gbatemp dot net/attachments/untitled-2-png.354140/
I’m quite a noob when it comes to both soldering and diagnosing a repair. I have generally all the tools needed to do SMD work and diagnosis, including a multi-meter and hot air gun, except for a way to measure Volts and Amps. If you have anything I could test or try, please let me know.
I’ve removed the chip. I’m having trouble getting rid of the flux residue. I use NC-559-ASM. If I put the light a certain way it’s noticeably there coated around the exterior of the components. It’s also affecting my probing.
See this image: gbatemp dot net/attachments/flux-coating-png.354187/
The 0:1.645~ I was experiencing with the top-most cap is no longer occurring at least. However, I’m noticing other strange behaviors now.
The cap I labeled previously as 0.345:0, is now 5.81~:0. There are a few smaller caps/resistors around the chip that I’m reading as 1:1 but I could just be testing them wrong or at the wrong range, or the coating of flux is interfering which I feel is more likely.
Any advice on what to do from here, or removing the flux residue?
With the 2x caps by the battery management IC still being weird, I’m quite worried. If anyone can advice me on what I could test to try and fix those, that would be great. The only thing I can think of trying would be to remove those caps and test their pads directly. However, would that actually be valid? Would it be possible for the capacitor itself to fail and exhibit this behavior? Is there other stuff I should test BEFORE doing that?