Matsuura MC-1000V spindle won't start flashing EMG

Yesterday while rigid tapping the tap bound up and generated an error. In my haste, I rebooted the machine and removed the tap without capturing the error. I thought maybe I'd bottomed out but it was actually maybe 3/4 depth. Now when I attempt to command the spindle it drops to EMG state without any error. I suspect it's generating an error but may be too fast to see. I've tried capturing it with my cellphone without any luck. It simply opens the contators and the hydraulic pump shuts down.

Is there an error log/history someplace?

Opened the cabinet and took a look. I have an AL-12 alarm on the spindle drIve.

I found this thread that covers some possible repairs.
https://www.cnczone.com/forums/fanuc...m-al-12-a.html

Not sure if I should send it out for repair or do it myself. I need to find the drive manual and take a look.

The AC spindle servo unit appears to be a 15S series.

Type: A06B-6059-H215#H517
No: ES1802604 A
Date: 1991-08

I think the service manual is GFZ-65015E. I'm reading the PDF now.

I found this page that has some abbreviated troubleshooting info.
https://www.gefanuc-spares.com/fanuc...r-alarm-12.htm

If anyone has done this repair I'd love to get your input.

It looks like I need to start by testing the A50L-0001-0175 IGBT modules. The machine indicated it was in high gear. But it should have been in low. I suspect it overloaded while tapping but I wasn't watching the load meter.

Replacing the transistor module fixed the issue. So far it is running perfectly.

I found it interesting how the heat transfer compound creeped out over the last 32 years. It took an entire 4 gram tube of Arctic MX-4. I had to work fast to get an even coat.

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