Hi,
sorry, but I bought this printer (WC7830) 2nd hand, and I have no support contract whatsoever... I'm always doing that since about 10 years, and I buy my supplies on Internet, too... for the +-15k prints a year, this is by far the cheapest option... Once the printer starts to make problems, I get a new one...
But still, pretty strange that this error is not documented anywhere... (excepted in the Phaser 7800 service manual, but I don't know if this can be transposed for the WC 78xx ???)
And it must be something serious, the printer stated itself that it was unavailable, and that power cycling was required...