My Switch OLED (picofly installed) had a water accident. I immediately opened the back cover and blowed it dry with a hair dryer. Afterwards, it still couldn’t power on, so I did some tests based on information I found here and other websites like retrosix.wiki. Below is what I found.
The 3.3V power regulator chip (max77801) got shorted. So I removed this chip and soldered two wires to inject 3.3V while waiting for the replacement chip.
With the 3.3V injected, I was able to boot to Hekate. A full backup of EMMC went through, so I assume the EMMC is okay. Battery info and USB charging current showed up correctly, so fuel gauge, BQ, and M92 should all be fine. I also checked the voltages around the max77620 chip and all seemed to be okay.
But from Hekate, I was not able to go further to boot either CFW or OFW. It would show the Nintendo logo then go black. I checked the voltage outputs around max77812. The 0.6V (LX4, lower right corner) which I believe is for the RAM came on immediately after power button is pressed. Then it booted into Hekate. If I tried to boot into CFW or OFW, the 0.8V (LX3, lower left corner) came on, which I believe is for the CPU. However, the GPU power on the upper side (LX1 and LX2 combined) showed no voltage output at all. I even connected a scope to see if there might be any transient voltage but nothing showed up. I tried replacing a new max77812 chip (BGA soldering is so tricky, had to do it a few times) but it gave the same results (only 0.6V and 0.8V present).
Anyone has suggestions on what else I can try? Is there any way to test the CPU/GPU within Hekate?
Thanks!