Hi all, I have been handed a phaser 7800 with an odd error, the machine boots as normal and comes to ready, no errors showing but if an internal print job is selected the machine says job has been submitted for 5 secs and then just returns to the ready to print screen. engine test from the service mode prints OK. Trying to print from the driver gives the same result; job submitted but no print is output. The machine had a boot failure and attempts to ALTBOOT FORCED-UPGRADE the firmware failed so the HDD was replaced, the machine then came to ready but would not accept firmware through the inbuilt web page or by Altboot on a memory stick. The last error shown in the error log is 341.347, service mode is normal but NVRAM reset changes nothing. So far we have changed the engine PWB the Hard drive and the main processing PWB all without effect, Why does Altboot and forced upgrade of firmware not work? Any Ideas?