15V/0.45 HAC-CPU-21, not booting

Nintendo Questions Nintendo Switch
1

Hi guys,

Got one of those “half ampere of death switches” again and looking for any troubleshooting tips. Thanks!

  • Current draw 15V/0.45A
  • USB port is okay and diode values okay
  • Couldn’t find any shorts
  • Voltage lines seem to be fine, eg 1v8, 3v3, VBAT
  • CPU/GPU buck voltages are normal
  • eMMC seems to be fine (checked with another switch)
  • Installed modchip for hekate. Does not glitch, gives error code short,long,long
    *== No eMMC CMD1 request (poor wiring, or dead CPU)

haven’t replaced M92 or fuel gauge yet

2

Any troubleshooting tips or is it dead CPU?

3

0.45a draw with the board by it self with no battery?
Could also be a bad nand or a nand connection issue, you could try the nand module in another switch (unpatched, don’t attempt to boot into hos, just rcm then hekate

If you plug the switch into a pc with tegrarcmgui open does it pick it up in rcm mode?

4

Thanks! I have checked the NAND with another switch. For bad NAND the modchip will give different error code.

5

Surprise surprise. The culprit was faulty M92. I removed the M92 and could run Hekate. After installing the M92 the switch boots.