DesignJet, Large Format Printers & Digital Press

I have been working on a HP Designjet Z6100.  It started getting a 08:11 error on it saying on the screen just the 08:11 Call Service as it was powering on.  I ordered a new Formatter for it and arrived to install it.  The user had turned it on shortly before that, and it was doing the power on process.  It came up fully, I checked the event logs and there are no 08:11 errors logged, and nothing recently has been on the logs since before it started.  When I arrived I was told that occasionally if it is turned off for a day or more it will come up as it did.  It successfully printed a couple jobs recently.  

But after printing off the log and checking it over, I powered the printer off then tried to power it on, I received the 08:11 error again.  It seems to just show a mostly blank screen with a border, then goto the 08:11.

I put the new Formatter in the printer and it still came up with the 08:11 error.  I am looking to order a replacement harddrive in for it, but it is on backorder so it will be a week or so till I get one.  Is there any other suggestion on the issue?  The manual doesn't seem to give a good indication of anything except "check cables", "replace this, then this, then this".   I was wondering if I should see about getting replacement memory as well, I didn't get exactly what type the memory was in the unit, if I have to order specific ram or if it is standard memory. 

The working after a day or a week of being off seems rather odd to me.  I have seen where some models atleast have some diagnostic leds on the boards does this model? and would that assist in narrowing it down?  Thanks for any help.