I bought a damaged switch board as I have a number of working consoles just in need of a new board.
So, when I first got it, it looked awful, but connecting it to a screen and working battery, it was able to boot to the OS.
So, I cleaned it all up, and started on the obvious repairs:
- Replaced USB
- Fitted USB Fuse
- Fitted 2 USB filters
- Replaced Left joycon connector.
At this point, it was still working as much as it was before, and I could find no obvious shorts, and the rails all gave the resistance values I expect on my meter. But I was not able to get any response from the charger. 0 amps drawn… or moving between 0, 0.02, 0.05, etc.
So, at this point I reflowed the M92 and swapped out the BQ.
This is where something went wrong. The heat needed to get the BQ off was also enough to have all the part on the under side of the board decide that the magnets on my board holder needed to be visited.
I didn’t lose any, so I put them all back in place. The light sensor didn’t survive, so I fitted the one from my parts board. The fuel guage had also moved a bit, so I just fitted a new one.
At this point it was not booting. Black screen, no backlight. No response from computer when connected with no emmc.
The only off reading I could find, was that now the 1.8v rail sometimes shows as a short of 0.8r, though sometimes didn’t and shows something like 3k.
I figured that it had to be something in the areas that I had been working on, so checked on my parts board which things connected to that line. As such, I then removed M92, (no change), removed BQ, (no change), removed the little 6 pin mosfet (?) on the rear side. This this point it initially still showed the short. But after it had cooled down it was back to reading 5k (my normal). But it was still not able to boot. So I put back on the BQ chip, but still not booting.
I put back on the M92 at this point, and the reading dropped back to 3k.
So, I think the M92 needs replacing, as it is dropping the reading, but I also believe I should be able to boot without it.
I can replace the 6 pin from one on my parts board, but again, I think this is used for the joycons, so I would expect to be able to boot without it.
This leaves me to think that it can only be the BQ (which was new) or the fuel gauge (also new, and fitting went well).
So, I guess I think I could do with some advise at this point before I make things too much worse. In the mean time I am going to go through some of the posts that covered issues in these areas and check some readings.