I have a 1996 Sabre 750 with the 2100 control and the BDS4/Kollmorgen drive setup. For the last year, the machine has been acting up at initial start-up. The machine boots and loads with no problem. But when it gets to the "machine power required" screen, hitting the green button again fails to power up the machine. Instead, it sits there for a few seconds and then brings up the following screen:
"Alarm 39-6
The axes drives ready signal [CR_AXES_RDY] and/or the servo ready signal [S_SERVO_RDY] have not been received within the allowed time limit.
Determine the offending drive. Make sure the power module is working correctly. Check the supply voltage to the unit. Consult the relevant drive documentation."
Now this problem started about a year ago. At first, I could just clear the error screen and retry to start it. This would work after a few tries, maybe 4-5 restarts. But the problem has gotten progressively worse. The other day, it took me about 75 attempts before the machine finally powered up. Now once it powers up the first time, you can turn it off and it will start right up again. You can let it sit for a while and it will start again. But if it sits overnight, the same problem occurs the next day. And the longer the machine sits (like a few days), the worse the problem the next time you go to start it.
I happened to have a service man here with a good amount of experience on these machines replacing the thrust bearings shortly after this problem started. He tested the output of the power supply and found it to be well within specifications. He tried to chase the problem more, but as with so many electrical problems, the issue never seems to happen when you need it to happen. It messed up a few times while he was here, but once it started the first time, the problem never came back for him to see it. I have also since tested it with a voltmeter and I see no voltage fluctuations when the machine is trying to power up, so I seriously doubt that the problem is related to the power supply.
Instead, it seems to me to act more like an issue with dirty or failing contacts, this would explain the way it is acting. The error seems to be related to the z-axis drive since the red light appears on this drive after the error pop up on the screen. The same technician suggested that the problem may be a relay related to the brake on the z-drive axis, but the documentation available to me is very limited, so I don't know what relay this would be.
If I had more documentation, then I feel as if I could probably chase this problem on my own. I am experienced mechanic, machinist, and engineer with degrees in both electronic and mechanical engineering. But without any information to understand how these systems function, it is just one giant black box. So if anyone can help me trace this problem, I would appreciate it.