Nintendo Switch First Boot Failure

[privato89]

Hello everyone,

I bought a Nintendo Switch (HAC-CPU-21) that was unable to boot. I discovered a short circuit on the VSYS line and identified the culprit as the integrated LCD driver chip. After replacing the chip, the short disappeared.

I attempted to start the device using a bench power supply, but it still wouldn’t boot. The power supply read 0.25A-0.3A and didn’t go beyond that. So, I began checking all the power rails near the MAX77620 chip. The voltages for the first and second boot are present, but the voltage for the VDD_1v05a power rail is at 0V.

I checked in diode mode and everything appeared normal. I also replaced the MAX77620 chip, but the voltage is still missing on that line when I start the console from the bench power supply.

I even tried reworking it, but the voltage is still missing.

Actually there is no short on the board. I also removed the usb-c port, and now it is removed.

Any ideas?

[privato89]

I noticed just now that there is a short on D+ line, it measures 0.070V and should be 0.74V. Extactly that line on the usb-c socket pad. That line goes under the CPU. That means there is a short under or in the CPU. Do you think it could be the cause of the problems? May be that a reball of the CPU can solve the issue?

[privato89]

I desoldered the CPU and tested the CPU pin and I found it was in short. That means that the CPU is damaged, I have now a donor board.