Hello,
i have board where only 21 chips found. Resistors around chips 21 and 22 are good.
I changed chip 21 and 22, but same result, only 21 chips was found.
I used this repair manual :
https://www.zeusbtc.com/manuals/Antminer-S19-Pro-Hash-Board-Repair-Guide.asp
Is layout chips different between S19 PRO and S19J PRO ?
Or chips from Alibaba are bad ?
.
Soldering is good, checked twice under microscope.
Thanks.
M.