There are actualy some posts about that around here,it's amasing how much can one learn in this place...there are even some posts with links to service manual downloads.
That's the purpose of this place after all,we share our experience and help each other,some tech's in here are certified some are independent,fact remains that there is loads of those machines out there and 2 few of us,don't just ask for solution but sometimes share what u allready know.
I meet all kinds of tech's every day,I'we seen certified Ricoh tech entering "flat line mode" over some ridiculos problem such as duplex jams...he is 2 dependant on bulitens and service manuals and culdn't see stupid spring missing on pressure rollers.
I allso saw independent tech making such mess like burning boards on machine...he mounted similar but wrong board...doesn't take a service manual or part catalog to compare 2 boards.
Turn on your logic boards and common sence,put your thinking cap and you'll be fine,service manual is a fine guideline but it's not alpha and omega.
Ok I admit i got SP7804 from service manual,yet my point is there's no need to diss Helios if he is new to all this,on the other hand he needs to learn how to "use this place better"