sinumerik 840D .

Machine works alterantely with error . Errors are enclosed at the pictures "error list 1" and "error list 2."

Why all axes with same error ? ( 3 rotating , 3 linear axes) . Before this , there were a couple of errors : 1. bad measuring of X and Y ( heidenhain linear system  - replaced ) 2. No communication PLC/NC -  uploaded old backup.  There is a similar machine close to bad working one , so I already swapped lots of hardware - mostly LT moduls with cards , IM 361 , power supply modules ...

Any idea what to do ? it seems like it could be some software problem , parameters ?? Anything has happened after upoading a backup ?

I'm enclosing another pictures that I took from good and bad working machine  , I do not know , I'm not very familiar with software of Sinumerik.

Thanks for any help from you .

Hello.

You say that you have exchanged the linear scales, did you exchange them to the same or did you have to use an alternative?

If you had to use an alternative, are you sure the signal is the same as the original?

Also does the machine have a Gear changing system?

This gear changing system could also be a spindle gear change system, and if it has is there a difference in the behavior of the machine when in Gear 1 or Gear 2?

Riddersholm :

linear scales are the same , with same signals ( track A,B ref.marks Z , sinus shape, distance coded)
no gears  ,  coupling of  motor of axes via  V-belt transmission to sledges

Nulizhang :

grinding machine , 6 axes 3 linear, 3 rotate ( X,Y,U  A,B,C)
NCU 57x.x I do not know exactly
there are 2 similar grinding machine next to themselves that some part of simodrive are same
after swapping same HW parts ( for example U/E modul , LT modules , IM 361 , +24 power supply unit , flat cables)
I placed parts back into original positions
One of those 2 machines works well , the second one worked well until the problems
have started .
1. problem  - dirty X linear scale  --> solved by cleaning   /  6 weeks ago
2. problem  - no reference marks of linear scale Y --> solved by replacing / 5 weks ago
3. problem  - Wait for connection to NC / PLC -->  uploading 7 years old backup of x.NC and x.PLC files / 2 weeks ago
After uploading backup I had to change software limits for linear axes , they did not work at right extent.
4. machine sometimes works ( even 2-3 days) , sometimes does not .
for example it works for 2 hours , then errors --> machine OFF/ON or NCK reset --> sometimes machine works , sometimes errors persist

For me , there is a big question : why errors are ( same ) in every axis

And , if there is only cross check of one axis , what to do then ? What to check? Hardware or

software ?

And , what about values of service axis/spindle screen ?   why values of measuring system 1

and measuring system 2 are different in bad working machine and same in good one ?Is this a clue ?