AR-M450 Drum Unit won't go back in all the way

[axyun]

Replaced drum and now drum unit does not slide all the way in. Stops about 1/2 inch short. I have only worked on thes a few times and I thought this happened once before but don't remember what I did. I got there late in afternoon and had to leave at 5. Took unit with me. Does something have to be lined up in back? When I push it in with the MC locked in place as far as unit will go. When I remove unit MC is loose.I"m sure I'll feel stupid when you tell me
what it is. /ActionP Frank

[blackcat4866]

Well, the left door must be open, then the lever lowered for the developing unit. It's not necessary to remove the toner and developing unit but I usually do. There is one thumb screw at the front. That's it.

Did you install an AR-451DR drum unit?

The drum drive coupler is spring loaded. If it doesn't line up perfectly and it usually doesn't the first time, you'll need to compress that spring, pressing the drum unit alignment pins to mate with the frame, then tighten the thumb screw. When the drum motor rotates the coupler will rotate and mate, reducing the spring pressure. Then re-install the developing unit, and toner, raise developer lift lever, close right door.

I hope I didn't miss anything. Is it possible that the primary charge is not completely latched into the rear of the drum unit?

=^..^=

[tmaged]

Try installing it with/without the main charge would let you know if that's it. Also try rotating the drum a hair. I recall having a problem with big round locating peg on the drum unit itself. I've had them stick in the frame & break off making it a bitch to get the drum out, so I imagine it could do the opposite.

[MHeon71]

If I remember correctly, the front cover of the process unit needs to be removed to replace the drum. There is a tab on the front cover that needs to fit under the process unit frame when reinstalling the cover. I have had the same issue. The part I am referring to is section 10 part # 22 in the manual.

[axyun]

When I examined the drum unit back at my office i discovered I had put the drum in backwards. I was stressed at customer's office as it was close to 5 o'clock and everyone was leaving and parking is ahastle and expired meter is $65.
I had it in correctly originally but after performing simulation 24-7 + 24-11 and installing drum unit I started to get a line and then several faint lines that looked like bias lines. I had also wiped off the transfer roller though i did this with a dry paper towel as I could not find cloth.
After getting lines I took apart drum unit again and to clean main charger grid etc. When I put back together asomewhat stressed out I put in backwards and perhaps thatis why unit would not go in all the way. I have to return this morning. Though the drum unit may go in now I don't know if I will still have lines. I don't have a transfer roller if needed . Could I have compromised the transfer roller and what should I do temporarily if that is causing the lines. Frank/ ActionP

[tmaged]

Frank, did you replace just the drum or did you also do the maint kits (KA1 & KC1)? I would think it'd be alright if you did the maint kits also. If not, and if you know what you're doing, you can sometimes adjust out quality issues by adjusting the main charge voltage. On these machines I'll sometimes have to do it or adjust toner concentration. These machines rely ONLY on rotation counts to adjust voltages to compensate for wear. That's why it's imperative to do all maint & reset all counters or you'll be in for a lot of problems. Customers cause enough problems for us.

[axyun]

I re-installed drum unit at customer's office today and it went in okay so it was because drum was installed backwards. There were still lines. I put in another new cleaning blade and then it was okay. Must have had defective blade. I generally try to install PM kits as needed but not always. Thanks again. Frank