Samsung SL-C460W has suddenly begun printing all black pages

[N0rt0n3]

This is crazy. This printer went from printing and copying perfectly,  to printing completely black pages. In fact, it appears the printer menu test pages print all black+color too. I cleaned the entire printer out: Transfer Belt + Fuser are spotless. No change...The only change thus far is Rebuilding/Cleaning the Imaging Drum...I printed a demo page and only half the page is solid black/color with a nice feathering in between. 
So yeah, originally I was printing a ten page report and on page 8 it went to all black pages. I'm now leaning toward something totally failing in the high voltage section of the printer...printer has three circuit boards
"I" can't find a service manual for this printer model so anyone have any thoughts on this?

[Copier-Pro]

Hi I would like to assist to the best of my ability to solve your problem.I hope the information i supply will be of help.

This means that the drum is not getting charged.Make sure that the contacts on the drum and other unit is not misformed on the High voltage board side.These contacts are normally spring loaded or just springs connecting on the board.It might also be a faulty drum unit.Hope this will help.

[N0rt0n3]

I'm surprised that you would say a drum, which has no wires or solid state parts, would suddenly fail.  Isnt it more likely a relay or laser or diode has failed when it suddenly goes from printing perfect to printing all black?

Remember the prints went from perfect to all black inside page seven to page eight so it cannot be possible that its the contacts that went bad.  Contacts only fail after drums or cartriges are removed then re-installed.

[N0rt0n3]

Service Manual says its not the drum, rather its the HVPS.  Replaced the HVPS and everything is fine.