Here is a clip from a post I was on 4-5 years ago. After tightening the mentioned shield clamps it never happened again.

"DTERR alarms can be caused by poor connection of the shield on the RP1 cable to ground at the controller."

"Yes the shield clamps were all loose in the cabinet. Tightened them and problem cleared. You people are life savers. I thank you."

I have had wires corrode off behind the battery, in the arm body. Acted the same way as op's.

CT's = current transformers.

Place current transformers on the axis feed wires and send to an analog card in PLC.

Then set max/min compare statements in program.

Have never tried with robots but I have done this on many other machines.

Are your robots using PLC's?

If so CT's + analog input + compare/compute statement and you could conceivably monitor current.

Not knowing full story behind this need for mastering I would suggest re-making the position and seeing if it holds.

If a robot loses it's master for some reason and the master is not saved correctly, as in recording the actual positions of each joint then remastering will usually require touch ups to positions.

If you care to share your email I may have something that helps.

Have you tested your control power from estop to control boards?

Do you have a back up PSU to try?

You said all the fuses on the PSU.

Did you check for a the small green fuse on the door?

Also make sure the transformer taps are in the correct positions for your incoming power.

Has this ran and quit or is it initial start up.
One thing that gave me fits in the past was baud rates.
They all have to match.
Good Luck

Comm issues with Wago and DNet board, try changing Baud rate on board and wago to 250 if set at 500 and vise versa. 1 st robot cell gave fits until I changed from 500 to 250 on both places.

DUP MAC ACK Fault after setup and ok comms, Check that plug on wago did not get pulled loose.

These are 2 fixes that worked for me at different times on my RJ2's. Good Luck.

Axis Limits: Menu>System>Axis Limits.
Actually in the post right below yours.
The search feature can be a real life saver in here.
Peace.

Was this robot previously running?

If it is a 420-i robot there are 4 D cell batteries in the base of the robot behind a 4 inch~ black plate with 2 silver screws.
The BZAL alarm means those batteries need to be changed and the alarm will not clear until you do change them and then follow the procedures already noted above.

I fixed this alarm, (2 years and counting) by tightening the shield clamps inside the control cabinet, on the advice of RacerMike . Knock on wood

What system exactly?

We looked at servo grippers and determined that they were so big and bulky that they were not feasible for what we do.
That being said they are powerful if that is the goal.

It will depend on your equipment. RJ2 will need KFloppy and specialized cables.

There are also driver chips on the mother board that can be blown by a short in your EE plug. They are very easily found if they are blown.
The driver-chips are two Toshiba TD62107 drivers.
They are located right behind the blue CRM10 and CRS1 connectors, and they sit in sockets, so they are very easy replaceble.
(Kudos to RacerMike for this fix when I needed it.)

Where your cables all enter the controller there is a bunch of grounding clamps that bite down on the cable shields. In RJ2 it is the lower left corner of the cabinet. Make sure they are all tight. I cleared this alarm once merely by tightening those clamps.