So far, so good.

Last Friday I opened all four servo amplifiers for a visual check. I found that one of them had two blown capacitors and another had capacitors with signs of high internal pressure. Being a careful man, I ordered new capacitors and thermal pads for all four amps and desoldered all 24 IGBTs to test them separately. They all tested OK so when the new components arrived yesterday I assembled everything and tested the circuit boards again. Almost as on que, the Vector Drive came back from Germany today with a new 25W pre-charge resistor for the 325V line (The old one had burned, causing the previous problem). I proceeded to install all components in the machine but tested the Vector Drive "alone" first, without anything connected to the 325V line. Now the big capacitors inside the VD charged up fine and the Fault LED went dark after a few seconds.

Switching off the machine again and waiting for the HV to bleed off, I connected one servo amplifier at a time and restarted to see if anything would go boom.

It didn't.

Instead the amps came up with green LEDs one by one and the machine started up accordingly when all amplifiers were connected, without any nasty error messages! It was a darn good feeling when I could execute the "S500 M3" commands and hear the spindle starting! All axis are also moving accordingly so the amplifiers are OK too. I did, however, encounter an error message (Spindle drive fault) when stopping the spindle, where it took "forever" to slow down and stop. Most probably (hopefully!) this is caused by changing/disabling the spindle retardation parameter, this was done as a part of the initial troubleshooting and never set back to where/what it was initially. I'll take a looksee at that tomorrow. If the problem persists I'll replace the Regen IGBT again, just to be sure...

And yes, the low voltage power supply I mentioned earlier is also fed from the 325V line, I found out when I ripped out the servo amps. This PSU feeds them with +/-12V.

So that's the situation at the moment. Although "It ain't over until the fat lady sings", I can see this machine back in production after Easter. May I not be proven wrong.

Best regards,

Gyro_Gearloose