IRB 2000-3560 with S3 M91A

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Dear all,
To my great joy i was able to make a boyhood dream come true and buy a robot.Although it is only a few years younger than me it looks to be in great mechanical condition.
The machine was previously in a safety enclosure, and held a silicone tool. 
After checking the wiring for loose connections in the cabinet (someone had tried to disconnect the optional wiring for safety enclosure) and replacing the 24Volts power supply the control unit boots up.
I have measured the voltages of the batteries, and they are both good after being under power for 2 days. The previous owner had luckily replaced these about two years ago.

It prompts some errors on the pendant, like:
506 Servo error 2 5104-7001
501 Parameter memory fault, reload!
502 Program memory fault
509 Sync error 2201

The robot is in calibration position in all axes, 
I first enter the motor types, then
When i try to follow the calibration procedure as prescribed in chapter 9.15 of the serivce manual i can enter a value for axis one, press update but no value is stored. 
The menu starts flashing and sometimes error "Resolver A2 Counter =-1 CPAR =- " is visible.

Any thoughts on how to take it from here would be tremendously appreciated,
Best regards, jef , belgium