That is a boot diagnostic menu and I have no idea how that would have come up in the middle of a print job. I'd reset the printer (turn it off and on) and see what comes up on the display then.
If you replace the main PCB you need to move the Key over or it won't post (grey squares on the panel with no fans on). It is a small 3-pin plug near the flash memory slot.
In addition to that if you have the V5 controller you would need to move the Flash memory chip and the DRAM.
After you do that you will need to load the microcode on the PCB. I can get you instructions to do this.
V5 MRP provides IT Parts Product Supplies and Services
V6 MRP provides IT Parts Product Supplies and Services
I'm assuming that you are using an IPDS device description. If so your Ethernet card need to have the defaults reset. There is an option to do this via the printers web interface.
