Explanation of mechanical components of Laserjet 3600n printer

[ianieto]

I know that the Laserjet 3600n printer is an older printer and has less current popular use.  I  think functionally there are mechanical components that are similar among most of the HP laser printers so hoping this discussion could be beneficial to many trying to resolve printer issues.  
To give a background for my case,  I am having some issues with my laser jet 3600n and I believe I am having main drive assembly (MDA) related problems after I accidentally removed some screws holding it together when I was trying to fix the cartridge locks.  I was trying to remove the MDA and took out too many screws hosing it up.  I tried resynchronizing the internal gears but have not been successful.  I have ordered a replacement MDA.  But there could be other issues.  I hear lots of clicking noises when the printer runs and I see lots of spinning parts that I don't understand what they do.  I wasn't sure if there are other gear syncing problems besides the external MDA gear syncing procedure described elsewhere.

I have looked online and understand the basics on how laser printing works and am fascinated and intrigued at the engineering of it all but was hoping someone can explain overall how each of the mechanical components work and what they do.  For example, what are all the parts in the MDA doing? I see it driving multiple things and being driven by some gears.  I also would like to know what the M1-2687-000CN developer separation drive assembly does with the two solenoids.  I hear the most clicking noise when it runs.  I also see gears from there driving the fuser mechanism.  I also see connections to the ETB unit to move the paper across the cartridges.
So overall, I would like to understand how all the mechanisms work together to control the process of printing.  I know this is a lot but was hoping there was an experienced person that could help with this.  Thank you.

[Valsimot]

Of all HP printers, CLJ 3600 is the most complicated model to explain.

MDA is used to engage and disengage the rotation of each toner cartridge and everything must be synchronized for a printer to create an image nad to drive some more parts needed for that process.

The developer separation drive controls the cams that engage and disengage ( open/close ) each toner cartridge. One solenoid is for black, one solenoid is for 3 color cartridges.

[ianieto]

Considering how the MDA seems to be in the middle of much of the activity and mine seems to be an issue, I will wait to do further debug of print quality until after I replace it.  Right now, I am missing some colors and the issue was not there before my breaking open of the MDA.  At least both of my original left and right cartridge lock/lever issues are fixed that caused me to open up the printer in the first place.
When it comes to the MDA motors, these seem to be independent of the other MDA functions.  Can someone explain?  

[Valsimot]

You need to make sure every gear is aligned properly or the printer will not work as it should.

http://www.lbrty.com/tech/instructions/ins3600mda.pdf 

[ianieto]

I previously did the alignments as suggested there but I think since my MDA was hosed, it threw things off.  I hope to get my replacement MDA tomorrow and will check the alignment again.  Would anyone know what those four gears that need to be aligned in that procedure do ( that go to each cartridge and open and close something on the cartridges for each rotation) ?

[ianieto]

I installed my newly received refurbished MDA and my printer is working perfectly now.  It is amazing how the unsynchronized gears can do so much.  I checked the removed MDA and the gear for one color had jumped out of place and was no longer synchronized.  There are two gears that are held in by the main gears for the colors and have been an issue staying in place since I disassembled the MDA.  I guess it is toast.

[ianieto]

I still would like a better understanding on the functions of the MDA.  I see a cable fed into the unit.  It looks like it senses the position of the large black gears.  Does someone know what that does?