Tsugami Mercury lathe with Fanuc 6T. Got this old beast cheap and repaired the mechanical problems. Am learning Fanuc programming. After several weeks of programming, got the lathe to make parts and was in the middle of editing a line and suddenly got a "401 SERVO" alarm. Found "HCAL" LED illuminated (high current alarm) on the X-axis (left side) velocity control PCB #A20B-0009-0320/07C. After much mechanical checking, found nothing. Swapped the 2 velocity PCBs and the "HCAL" stayed with the PCB. I have been trying to troubleshoot to find the component(s) responsible, but need a schematic to go farther. The ICs Q3, Q4, Q5, Q6 and some of the resistors in that area have fantastically different voltages between the two PCBs. Again, swapped the PCBs and the voltages stay with the PCB. I believe the problem is on the PCB, not in the axis drive. Any ideas? or can anybody supply me a schematic diagram? I tried first with GE Fanuc and had NOOOOO luck. Also had no luck trying to connect the 6T to a PC so I didn't have to stand at the control, but no luck. If this problem can be solved, I will be back to trying to connect to RS-232. Thanks for any help!