Checked all pins of m92 for proper connection to the surrounding components (caps, resistors) with multimeter and think it is properly soldered on
Checked with USB-C checker again - short on pin 5(ish) was gone - also checked usb-c connections via breakout board. All connections fine (realised a bit higher resistance of around 3 ohms for the D+ and D- lines though).
Now when i plug in the charger via usb-c i get 5V 0A on the power meter. Console does still not power on.
Measuring the path of VBUS i realised that VBUS is present until after the fuse. But it is not present after the FET.
Continued investigation by injecting 4.2V into VSYS. All Stage1 Voltages are present at MAX77620 - 3.3V are present at ENXX aswell. Pin5 and Pin6 of M92 show 3.3V (which should be fine). Current draw stuck at 130-140mA
Switching over to injecting 4.2V into VBAT with 10K temp resistor in place.
Same behavior - Stage1 voltages are present - Stage2 voltages are missing - stuck at 130-140mA. Same with EMMC disconnected (for stage 2 test i connected it of course).
Verified that BQ is ok by injecting 5V into VBUS while a real battery was connected - got 0,46A current draw (battery was charging).
So basically i have 2 issues at hand.
VBUS is not making it through the FET (or maybe the FET is not activated by M92)
Console is stuck at stage1 (it doesn’t seem to be in RCM either - at least it is not detected on my laptop…)
I think that my test number 13 should also have tested the fuel gauge ic right? It would have been the next chip to replace by looking at the current draw.
Might it also be a problem with M92? (yes i got this from ali express - also ordered another one from another distributor in my country just in case …)
I have investigated the CC Lines which are responsible for Voltage negotiation and compared it with a working console.
CC Line ist around 1.17V (giving 5V on the charger). There is an ESD protection circuit on this board but I don‘t think it is faulty because I would expect short to ground for the CC line then.
On a working console CC line is about 1.67V (giving 9V from the charger - it’s a 12V charger so this is correct).
Also I tried to measure if the FETs are driven from M92 which they are not.
I have the feeling that the M92 is just dead and does nothing. I could remove it and try to drive the FET manually - but I don‘t know which voltage it should get to switch.
Connections to the 2 FETs (over voltage and discharge) from M92 are fine though.
After ignoring this switch for some time I thought about it and came to the conclusion that based on the repair history it could only be the M92 chip. So I decided to reflow it first which didn’t change the problem. I then took it off again and replaced it with one bought from a local online store (a bit more expensive too). After that I was greeted with proper 15V and 470mA draw.
The console still came not up and also didn’t enter RCM when plugged in without battery and EMMC. So I forced it into RCM and it loaded Hekate properly. From there I was even able to start semi-stock from sysnand. But it was not able to boot stock without Hekate. Somehow the boot loader seemed to be messed up (fuse count was correct for the installed HOS Version).
In the end I gave it a system reset and it was then able to start on its own.
The switch was on 12.01 initially - I updated to 19.01 and I seem to be able to reproduce that „stuck“ situation.
If I try to boot into recovery (with Vol+ and Vol- + Power) it does not go to recovery but just goes to a black screen (it is not in RCM then).
From that point on it is not able to boot into OFW - only via Hekate into Semi-Stock.
Once I do a factory reset it will boot into OFW again without SD Card and without Hekate.
I wonder if the BCPKG2-5-Repair-Main and BCPKG2-6-Repair-Sub images are corrupted somehow. I might try to replace those 2 with ones from a switch with working recovery mode to see if I can fix it.
It’s getting even stranger. I think I was miss interpreting this behavior. It only boots ofw as long as a left Joycon is attached. It will get stuck in black screen without left joycon (works with hekate though).
It worked after factory reset because I attached Joycons for that.
I disconnected the Joycon rail and it still prevents a boot to ofw. So I think it is something electrical (not software) that is wrong and gets apparently fixed by inserting the left Joycon …
Another update. I was about to measure some voltages but didn’t find anything usefull. Because it was late i somehow managed to drop the whole switch to the ground.
Well i was lucky i think. It still was working and the issue that it didn’t boot without the left joycon was fixed too by the drop (WTF?). So its booting to OFW no with or without joycons - so far so good.
But i still have a (new?) issue with the left joycon. It works docked and undocked and is also detected when attached to the rail. But it does not give the snap sound and animation when put into the rail.
I also think it does not charge but am a bit unsure about that because the battery might just be too full. (its chown as 100%)
I have then replaced the PU IC for the left joycon but it didn’t change anything. @Calvin i know you had this issue too at one point a couple of years ago where you suspected a faulty SOC or SOC pad.
Did you ever find the solution to the missing snap sound / animation by any chance?
No, I haven’t found a solution for the missing snap animation. Because evreything else is still working, I never came back to the topic to investigate further. But maybe with the new board views it is possible to track the issue down.
