su-42118-6 error with ps4

Things i have done:
Replaced ribbon cables to Blu-ray drive

Verified correct 12xx gen drive and original daughterboard

Swapped in multiple hard drives

Replaced the power supply (PSU)

Replaced thermal paste

Replaced antennas and power connector

Verified all cable connections and seating

Inspected daughterboard for visible damage or issues
Tried Rebuild Database

Tried Initialize PS4 (Factory Reset)

Downloaded and used the correct full reinstall USB file from PlayStation

Tried all Safe Mode options (1–7)

Tried with just the daughterboard connected

Tried with disc drive completely unplugged
Error SU-42118-6 still appears in all cases


My only remaining troubleshooting that i have not done is to verify the Syscon if it might be a corrupted Syscon or Drive Pairing Data

Dead Southbridge
Trace Damage (Though through visual inspection i have not found any damaged trace)

Does anyone have an idea for what i can do. Reballing the southbridge might be an option.

Flashing the Syscon/NOR/Nand