laser-lovers@uw-beaver (04/17/85)
From: jjhnsn@ut-ngp.arpa (J. Lee Johnson)
We have experienced a problem with our Imagen 8/300 that is very similar
to the "smudgies". We get one band that runs vertically down the page
about 2.5 inches from the left edge of the paper. The band is about 5/16
inch wide, and is definitely more pronounced on the lower half of the
page. As with the problem reported by Henry Spencer, the page looks fine
except for the gray band in the background.
Observations:
1. Changing the print cartridge has no effect.
2. Smudgies appear with both manual and automatic feed.
3. Smudgies appear only around glyphs, clear areas of the page are clean.
4. The smudgie band is already on the paper before it enters the fuser.
5. The gray band does not move when the paper is rotated in the feed tray
(i.e. it is not a flaw in the paper)
6. Changing to a different type of paper "cures" the problem.
The only physical structure of the printer that correlates to the
location of the smudgie band is a solenoid back near the paper feed
slot. Of course, since I don't have a service manual, I am not sure
where to locate the "Plate, Fusing Feed" mentioned by Jim Potter.
One correlation we were able to make is that we had started using some
"reproduction" paper supplied by a user. Changing back to our old paper
"cured" the problem. Actually, we occasionally get some light smudgies,
but nothing like the distinct smudgies we were previously getting.
My hack theory is that a combination of variable paper quality, poor
power and grounding, failure of the Canon engine to completely
discharge the paper, and magnetic interference from an aging solenoid is
causing our problems. I'm going to check the "Plate, Fusing Feed" as
soon as I figure out where it is.
--
James Lee Johnson, U.T. Computation Center, Austin, Texas 78712
ARPA: jjhnsn@ut-ngp
UUCP: ihnp4!ut-ngp!jjhnsn allegra!ut-ngp!jjhnsn gatech!ut-ngp!jjhnsn
seismo!ut-sally!jjhnsn harvard!ut-sally!jjhnsnlaser-lovers@uw-beaver (04/19/85)
From: jp@LANL.ARPA (James Potter) > From: jjhnsn@ut-ngp.arpa (J. Lee Johnson) > > We have experienced a problem with our Imagen 8/300 that is very similar > to the "smudgies". We get one band that runs vertically down the page > about 2.5 inches from the left edge of the paper. The band is about 5/16 > inch wide, and is definitely more pronounced on the lower half of the > page. As with the problem reported by Henry Spencer, the page looks fine > except for the gray band in the background. > > > Observations: > > 1. Changing the print cartridge has no effect. > 2. Smudgies appear with both manual and automatic feed. > 3. Smudgies appear only around glyphs, clear areas of the page are clean. > 4. The smudgie band is already on the paper before it enters the fuser. > 5. The gray band does not move when the paper is rotated in the feed tray > (i.e. it is not a flaw in the paper) > 6. Changing to a different type of paper "cures" the problem. > > The only physical structure of the printer that correlates to the > location of the smudgie band is a solenoid back near the paper feed > slot. Of course, since I don't have a service manual, I am not sure > where to locate the "Plate, Fusing Feed" mentioned by Jim Potter. > > One correlation we were able to make is that we had started using some > "reproduction" paper supplied by a user. Changing back to our old paper > "cured" the problem. Actually, we occasionally get some light smudgies, > but nothing like the distinct smudgies we were previously getting. > > My hack theory is that a combination of variable paper quality, poor > power and grounding, failure of the Canon engine to completely > discharge the paper, and magnetic interference from an aging solenoid is > causing our problems. I'm going to check the "Plate, Fusing Feed" as > soon as I figure out where it is. > -- > James Lee Johnson, U.T. Computation Center, Austin, Texas 78712 > ARPA: jjhnsn@ut-ngp > UUCP: ihnp4!ut-ngp!jjhnsn allegra!ut-ngp!jjhnsn gatech!ut-ngp!jjhnsn > seismo!ut-sally!jjhnsn harvard!ut-sally!jjhnsn Sorry, I neglected to be more descriptive about the location of the Fusing Feed Plate. Open your LaserJet. Inside, behind the Fuser (the thing with the green cover) there is a black, ribbed gizmo about 8.5 inches wide and 4 inches front to back. It is located just after the corona transfer wire (the thing you're supposed to keep clean). The blacke, ribbed gizmo is the culprit. It is held in by 4 phillips head screws. Simply, unscrew these, remove the thing and observe that it is really two pieces, a plastic one and a metal one. The metal one fills the space between the plastic ribs. Locate the approximate position left to right that is associated with the smudgie. Deform the metal plate SLIGHTLY in such a way as to make it stick up through the ribs a bit further. Replace the assembly. VOILA! No more smudgie (or you missed the location or weren't brave enough when you deformed the plate). Please don't send me the bill if you screw it up. Just tell hp that you know the secret of the smudgies and would the please send you a new Plate, Fusing Feed Assembly part nos. RF1-0164-000CN, FA2-5927-000CN, and (optional static eliminator) FA2-5928-000CN. You might also get a manual pn 02686-90904 if you are going to maintain the thing yourself. Price is supposedly $50 unless they like you. I just noticed in the figure a little part called the STUD. It is a little plastic button mushroom with stem that sits inverted under the Plate, Fusing Feed It looks like it might be used to keep the three main parts lined up. I wondered what that little piece of plastic mushroom thing I found on my desk the other day was!!!! Jim Potter jp@lanl.arpa