Ineo750/bizhub750 error C-4707

[Gleq]

Hi all
This develop ineo750 same as bizhub 750 with error code c-4707
the manual says the abnormal part is one of the ff:

write unit
ipb (image processing board)
scb (system control board)
prcb (printer control board)

Now its difficult to isolate the problem b'cos i dont have parts to check

any info to help me pin point the exact faulty part?

thanks