[Biruslapio]

Ok, I'll go into more detail, check these circled components.

On the Y-SUS these 5 pin optocouplers drive the IGBTs, they cannot be shorted, also there are some 2.2, 10 and 100 OHMs SMD resistors next to them that fail, the IGBTs and MOSFETs gate resistors are circled too.

On the top picture the "fusible" resistors are marked and cannot be open.
These procedures are valid for the Z-SUS.

This model has buffer boards failure quite frequently, it's important to test them. During power-up you can measure VSCAN, -VY and ZBIAS to see if they are stable and matching the panel sticker.