I solder a new P13USB tomorrow, i check the pins 35-38 in diode mode and all measurements are OK.Have you got a new PI3USB to try and check your soldering on pin's 38,37,36,35
if the solution from @Mightyjebus doesn't work, check if the solder joints of these caps are REALLY touching the caps. I once had an issue that a solder joint was broken and this caused the same issue as you described it.
Thx for reply, what temp and how long did it take you? I work on phone board more so I am not familiar with larger board apu like NS. I used 250 degree for over 5 minutes as suggested online to see if reflow apu would make any difference since I dont have stencil now, nothing so far. I want to try 300 degree next. Sugguestion?pls see --> https://gbatemp.net/threads/nintend...g-soc-nvidia-tegra.556346/page-2#post-9059323 for reballing the CPU :-)
Hi and sorry for the delay.@Crossfader did you try my suggestion from 06.06.20?
Thx for your detailed reply, I ordered the stencil, but under current situation, who knows how long it will take.yeah, I had the same issues at the beginning. make sure that you're really using a bigger noozle than the one for the phones or the M92T36 ic on the NS so that you can apply the heat on a wider area. I do it always like this:
1. Apply some flux
2. Heat up the CPU/APU with about 400° until the solder gets soft (this usually takes 3-4min and I need this temperature with my hot air station since I haven't got a board to preheat the NS mainboard)
3. Use this tool (https://de.aliexpress.com/item/32846496929.html?spm=a2g0s.9042311.0.0.55134c4d8lUEDD) or anything similar to lift the CPU GENTLY from the board
but be very carefull when you lift the CPU so that you don't damage any pads on the mainboard or on the CPU. afterwards I do a reballing with the stencil and then you can easily put it back on the mainboard. So far I wasn't able to do a reflow since the factory solder needs really high temperatures to get soft and therefore I do a reballing always. maybe @FXDX has a better idea? ;-)