Hi David,
Welcome to Robot Forum!
Do you have access to all the manuals for this robot? If not, I can find a way to share them with you.
From my understanding, Error 106 is a result of the lithium primary battery in the controller going dead. You can reset the RANG values all you want, but if you don't replace the battery then it will continue to lose memory. I do see you stated you replaced the controller battery, but worth a double check of both polarity and voltage.
If you have not done so, double and triple check all the connections in the robot body per the maintenance manual.
Can you tell me the full part number of the RC3 controller (such as RC3-V6A)? There are dozens of robots supported by the RC3 controller family, but the controllers are different configurations for each one. You would need the RC3-V6A controller to run a VS-6354 robot.
The memory clear procedure provided to me by Denso is as follows. I did not need to perform this, as my controller battery never died.
1) RC3 All clear command to wipe out memory area:
Press [BCLR] [1409] then [Enter]. Then Press [Sure] then [Rec] keys.
2) Clear all programs and variables:
Press [BCLR] [123] then [Enter]. Then Press [Sure] then [Rec] keys.
From there, you should be able to power cycle the controller without getting an Error 103 or Error 106 when first powering on the RC3 controller. (Owners Manual A, page 6-15 thru 6-18)
At this time I would also double check the robot encoder backup battery voltage and polarity. You can verify this at the motor connector inside each joint of the robot. Make sure all 6 motors are getting 3V. (Owners Manual A, page 6-13 thru 6-14)
Now perform the encoder reset procedure (Owners Manual A, page 6-23 thru 6-29).
I found if you have not configured PLIM, NLIM, and RANG, then CALSET may fail. Start the Limit Definition Procedure (Owners Manual A, page 5-82 thru 5-87). Note that after you finish entering the PLIM and NLIM values per the manual the RANG1-RANG6 values are the next to show up. The manual does not tell you how to enter or modify these, but this is the time to enter those values from the sticker on the base of your robot.
If this works it is time to CALSET the robot (Owners Manual A, page 5-88 thru 5-95). I did not have the J6 Calibration jig, so I had to develop my own method of calibrating J6 by measuring the angle of a flat I milled onto some end of arm tooling relative to a flat plane. It isn't perfect, but it works!
If you have gone through these steps and are still getting stuck, please record you exact steps (keypresses, actions, etc.) and the resulting error codes displayed on the pendant. I'll dig in deeper to see if I can help.
I'd love to see photos of your setup if you are willing to share. Do you have any of the accessories like the operation panel, floppy loader, vision system, etc.?
Good luck