Konica Minolta C6501 print problem

[grafarts]

Hi,
Recently I have changed the faulty main board (OACB) of my printer (C6501). After that the it takes prints only upto 135gsm. If I gave higher gsm above 135 the printouts are damaged. (Image attached). Kindly help me.
48462

[Toxic]

Strange one.
What was the reason to replace board?
OACB is new or used from other machine?
Did you try to reload firmware after replacing OACB?
What is current firmware?

More information you give, more chance somebody figure out what can be problem...