Lj 4100n 55.0 Printer Error

[chronictrees]

Can someone please help me figure out what this error code means? So far i've found that it might be the formatter and or firmware dimm or the engine controller board. If this is correct can someone tell me where I can find p/n's for those?

[ptjeff1]

Internal communications error.
1. Check the power at the location. Make sure the printer is not on a battery backup.
2. Remove JetDirect cards and see if it persists. Try another firmware dimm if you have one. Then try another formatter.
3. Replace the engine controller
board.

We have all of the parts, but if you have another LJ 4100 it would be easiest if you could swap firmware then formatter to narrow down the problem.