I posted this to the Gecko official support forum but it appears to be underutilized so I thought I'd post the question here in case anyone has an answer or comes across the same issue. I have a Gecko G540, and a Nowforever VFD to drive my spindle. I misinterpreted the G540 manual about the +10V the G540 is expecting from the VFD. The VFD I'm using only has a 12V out which reads more like 13.3V at the terminal. When I hooked everything up, the remote frequency control of the VFD through the G540 didn't work (although thankfully the forward run pin still works allowing me to control spindle on-off). I've read posts online about the issue suggesting that I may have damaged the VFD controller circuitry in the G540 with the 13.3V instead of 10V. Is there a quick way to test if this function is damaged beyond repair?