T830 not initialising with error 0009-0301 on screen and 0027-0059 in log

[bestoday]

Designjet T830 has developed an error code 0009-0301, after a scanner document jam, which makes it not initialize after HP logo. Manuals say that the scanbars have issues. After inspection noticed one of the bars had come loose from its clip system and dropped on one side. Reinstalled it and it appeared fine. Unfortunately, error code reappeared after unplugging, (as it stalled on 'shutting down' screen). Although, sceptical, I concluded that the scan bar must have been damaged from document jam and ordered a new set. Now after correctly changing the part the printer hasn't responded,

and developed the error code 0009-0301 again. As it won't allow 'extended support mode', I managed to enter 'Support mode' by holding down the power button, >15secs

On checking the error log, I noticed a hidden error 0027-0059 'Printhead- PHA error missing' occuring alongside error 0009-0301

Removing, checking levers, and reseating printhead hasn't worked and all seemed to be mechanically ok.

But after restarting it again goes to the 0009-0301 error, with 0027-0059 appearing in log.

Will an OOBE reset help? I am reluctant to order a printhead at this stage until I'm sure.

Anybody seen any printhead  missing issues or faulty printhead lock levers on this printer.

Any advice most welcome as I am at a loss. 

Thanks in advance.

[bestoday]

Anybody with any suggestions?

Just an update, I completed OOBE reset and now printer will complete proper 'Shutdown' but nothing else has changed. 

Just one other thing is that printhead carriage stays in the middle after shutdown without capping by service station.

Printer is still OOO as before, producing the same error code sequence on reboot.  Scanbars cost >€400 and I still can't be sure they were actually faulty, as replacing them still produces the error code. Unable to complete 'promote PRNU to pristene', as can't enter extended support menu. Printhead assy could cost even more, so I want to be sure a new one will resolve the problem.  Please help?