Hi all,
I wanted to share my scenario!
HP CLJ 2605dtn - 79 error after firmware update (... unless it started due to hardware fault, and then a fellow techie flashed the 20120413 firmware to try fix it, not realising that it was a hardware fault, and is one big coincidence)
anyway... I re-flashed 20120413 - got error 79 whenever a job is sent to print over USB/LAN/report prints from system config etc.
downgraded to 20071108 - same issue, reset NVRAM, same issue
downgraded to 20060510 - same issue, reset NVRAM, still the same, error 79 all the time.
might work for 1 print, or 5, but 79 always came back.
got another working 2605 spare which still had 20060510 on it, to try some parts out of to fix this other one.
I tried another "DC Controller" board (mistakenly thought this was the formatter board) - still the same with all 3 firmwares (starting with 20060510 as that's what the spare-parts printer had) and worked up to 20120413 - all the same, random 79 errors.
I swapped the Formatter board, with the spare - no problem (except alignment off) - all worked fine.
reset NVRAM - alignment fixed, still working fine.
updated from 20060510 to 20071108, reset the NVRAM - no problem all working.
I put the original faulty formatter board back in, downgraded to 20071108 - error 79 again.
NVRAM reset - error 79 again.
I stuck a standard 10cm PC case fan pointing at the formatter board... et voila... no more error 79.
all working fine - might be something for you all to try if nothing else has worked............
perhaps the firmware just highlighted failing formatter PCB's... the HP chip does get very hot regardless of firmware used....
so with an apparently overheating/failing formatter board and a PC Case Fan, I've sent every large / complicated document at the 2605 i can - even 4 per page, duplexed - and it's not error 79'd again yet.
I'm going to try the known-working formatter PCB again, but flash it with 20120413 for the first time, and see what happens - i'll post back in a while.
my personal and professional opinion is that you shouldn't be getting so worked up and blaming HP for your own reliance on an 8 year old printer (financially in terms of toners, and professionally in terms of requiring it for a business)!!!!
anyone got anything else they'd like me to try to see if it helps them?