grease for carriage rod designjet T120

[SHThompson]

The head is considered to be a consumable so it is treated different than a part.

I have found some pictures of the carriage online and I cannot see a carriage board in any of them.

[marpveg]

the board is in the carriage, hidden, you can find confirmation on the service manual, called PCA carriage.

from above you can see an LM358 chip that contains two op amps, I've used it recently

the printhead board, have no chips

[marpveg]

the electrical schematic would be useful to understand if the print head is driven by a chip from the PCA carriage board or directly from the  main PCA

[marpveg]

SOLVED

changed printhead, and printer works.

Printhead was shorted.

Thanks to SHThompson, who gave me the information that never changed the carriage, but only printheads on these printer models.
I accept it as a solution