Fabtek 153 iqan problem

[Skidder Kev]

Hi everyone been awhile being on here.    Lots of knowledge on here so figure I would pick your brains.
Got a 04 fabtek that we have been running for a few years now and just having some small problems that we are working through but it has been good so far....till a few weeks ago.   
So working some plantation pine and the hyd function would just die.   No joysticks or foot controls.   Iqan screen would be locked up, engine still running.  You shut it of and restart it and it will be fine for the rest of the day.   That happen for 2 weeks off and on then 1 day it went off and wouldn't reset.    Would thought the iqan computer was bad (black box)  after doing some checks and calling a few people.    Soon we replaced the iqan with a used one and BOOM! it worked for about 4 days then the samething started happening again.   It eventually just froze up again and all the screen says is "parker" .       Anyone have any insight on this problem or have it before?  
Thanks Kev