Before I throw more money at this, I thought I'd check here first to get others' perspectives.

I bought a KBDF-27D VFD and a 1.5kw spindle for an Avid Benchtop Pro router, mainly because I currently only have access to 115V, I have a minimum requirement of ER20 and the spindle body was already tapped in the right pattern for mounting on my machine's Z. It will draw a maximum of 17A at 115V, and I doubt I will ever use it at full power. If one day I am able to use 220V, its power will match the spindle's.

Like an idiot, out of curiousity I plugged the VFD into a step-up transformer without changing the input wiring at all and it fried the power board. I disassembled the drive and unsoldered all four electrolytic capacitors, and replaced them with identical new ones.

The drive now turns on again, but I get an "SC" error, which suggests the motor windings are shorted even though there was never any motor connected after I plugged the VFD in for the first time after repairing it. Any idea what could cause this fault inside the VFD? Can this be fixed? What components should be checked and/or replaced? Can I clear this fault?

I tested the motor pretty much the only way I can: I clamped meter leads to pairs of motor connections and spun the spindle by hand. Each of the three combinations of pairs of windings gave similar voltage results, and seemed fine. I seriously doubt the spindle motor is damaged, but how else can I check?

The spindle only cost US$240 to my door, and the KB VFD was about the same. I'm trying to decide whether to sink more cost into getting this to work or just replacing everything before I lose my mind.

What would you do?