Switch not charging or slow charging, not turning on, RMC problem too

Ughh, guys. There is a lot to say about this one. I’m rather iphone guy than console, but managed to solve few switches already.

Those are the facts:

  1. Battery IC Shorted, short is gone after replacement
  2. On USB outputs and fuse near USB I got 5V (wonder if that’s ok or should be 15V infos about that are mixed)
  3. On baterry connector getting up to 4.2V
  4. Console is taking only 0.4A
  5. After connecting battery and trying to turn on. Nintendo logo flashes, then screen goes dark, no backlight.
  6. When holding on power button and volume + and - all together, charging symbol with blitz flashes, then screen dark.
  7. Recognized by PC as Nintendo Switch when cable is plugged
  8. When I try to enter into RMC, it’s not recognized
  9. Without memory chip it’s recognized straight away

Any clues, no idea on what firmware version it was, serials starts with XAJ4005