That's weird, almost the same post was made for a T17+ just a short while ago. Response is roughly the same tho...
A - Can we see the message indicating three three simultaneous pic malfunctions?
B - What is the voltage across the first and the last pins of the PIC?
The chances of three simultaneous PIC malfunctions are pretty miniscule, a better explanation is that the control board is not supplying the voltage it should to activate the PICs it needs to communicate with.
P.S. We call the code a PIC runs "the HEX" and the code the controls board runs "the Firmware"(even though technically they are both correct terms for both devices).
Yes, is it weird.
1. Damaged Control Board - Shorted enable signal (EN) to GND from SoC to TL5209 (3V3 regulator) and damaged nand flash ( i have dump from another control board S19j pro ) - (MAC address is not stored in nand flash) so i replaced soc and nand flash and control board boot up correctly.
2. Then control board couldn't read data from eeprom on hashboards, ARC tester, i tryed REVELPROG-IS bud same result, cannot connect to eeprom.
So i changed eeprom and writed "s19j pro data" from my backup.
3. third problem, control board couldn't read data from pic controller. I de-solder PIC and same issue as eeprom, couldn't read data from PIC.
I have PIC HEX back up from S19 PRO and S19. But i don't know if HEX files are same as S19j PRO.
M.