Alright, this might take a bit of explanation, but I think by the end maybe there will be a complete picture as to what has been done and what might need to be done.
I have a V1 switch that was attempted to be modded with a modchip. The person modding it knocked off 2 resistors under the power button/volume button connectors. They also fried the LCD, Fan, and Power button/ volume button connector. I replaced the power/volume button connector at the same time as the resistors and the buttons work fine. To my knowledge, and from testing, the resistors only had an effect on the power button and the volume button, NOT the fan connector underneath it.
Now, from testing that I will describe shortly. we discerned that the connectors are fine, although a lot worse for wear they are still functional. We turned our attention to the M92 Chip, where there was an attempt to hijack the 5v rail at the M92 to power the modchip. They knocked off two of the capacitors (pictured below) , I replaced them with the proper values (been over a month now so I don’t remember the exact values, but I did some extensive research before getting them and putting them on), and the switch powered back on. GREAT! But no joycon charging (Joycons were dead, well below the 50% threshold that you would see the charging stop at when undocked/not charging the switch itself). Then no fan either. Typically the switch will throttle down it’s clock and there won’t be as much heat, ie no need for the fan to turn on when not hot. But I stress tested it, I left it unplugged and had the switch completely reassembled, tossed in BoTW and loaded up a save at the top of one of the towers, played for about 5 minutes (typical time the console would get hot, and kick fan on) and no fan came on. I decided to send it off to a friend, who is where the next part comes in.
After sending this thing across the US/CAN border, I was hoping a friend of mine who does more microsolder work than I do (mods switches and Xbox on GBATemp as a trusted seller) would be able to fix it when he told me to send it his way. He came to the same conclusion that I did, reflowed a couple of components better into place than I could, and plugged the console in. He was able to get the fan spin and joycon charging pretty consistently at this point as long as it was plugged in, but sent me a picture and noted the caps were shorting to each other and potentially running up another trace and shorting a resistor somewhere close to the M92 chip. He has decided that there might have been a short to the M92 chip, as well as stating that the LCD connector itself is pretty fried from all the work up there before either of us.
So, now that the story is out there, here’s what I am asking. 1.) Replacing the M92 chip, as well as the capacitors and the resistor that is near the M92 seems to be the right course of action. I have the tools here to facilitate this, and at this point my Canadian counterpart is at his witts end and is sending the switch back my way. Can anyone confirm what they would do in this situation/what testing they would do to confirm what we suspect. 2.) I was under the impression that the switch can’t even boot up without an M92 chip functioning. I also see the system immediately pull 5v at 0.4a using a USB Volt/Amp meter when plugging the system in (Expected pull), does this indicate a partially functioning M92/fully functioning M92?
Mainly just trying to avoid doing any additional work to this that doesn’t need to be done. Looks so far from what I can see that the board is still in tact, but I don’t want to put much more stress on it.
Picture of affected area: imgur. com/a/C6bS6iO
Picture Description:
CAN friend reflowed M92 chip(thus the nasty looking chip. Might be fried now lol, but does still boot and charge controllers /fan spin when plugged in)
on the left there are two blue tick marks. These indicate shorts that he found that weren’t easily visible on my scope, but were on his. There is a short from the bottom cap to the top cap, and a short from the top cap to the resistor above it.
Then looking at the red lines, these would be the indicated shorts based on the description above. On the left we have the two pins that the respective caps are connected to that would have bridged as well as going through the board layers we can see the trace would have also shorted the two resistors on the top right of the M92 chip.
I have already ordered 2 M92 chip replacements, I still have replacement capacitors, and will swap them out immediately upon return. Outside of this, I would need the values for the resistors shown to get them on order, at which point I would wait until they arrive and replace them as well. Finally after this I would try and plug the switch in, see if we get charging/proper wattage, and then try to power it on as a final test.
If there is anyone that wants to take this on instead of me, that’s cool too. But I am counting on having to fix this one on my own.