Same as My trouble
How do you repair it ?
your log is mean No voltage in Domain 7 (Column

but mine is No Voltage in Last Domain 12 (Column 11)
i Change LDO 8 pin and LDO 4 Pin still Not working
how about you
That's pretty bad did you touch directly the board to replace regulators.
Anyway, what things did you do first before you replace LDO?
Sometimes the signals from logs are due to a connection problem between the hashboard and the control board. Replacing the cable sometimes solves the issue.
But if you already tested them and run the miner one by one to test if each hashboard running fine without the other two hashboard connected. If the result is still the same the hashboard is broken.
You can follow the whole troubleshooting guide from here
https://www.zeusbtc.com/articles/information/184-antminer-t17-manual-downloadCheck the diagram and PDF guide just translate them into english.