Laserjet 4mPlus horizontal line printing

[roar514]

HI,

I just got a laserjet4m plus, That was trow away with the duplexer,
envelope feeder and a new toner because of a frequent paper jam problem
so i decided to try to save it. I cleaned all the roler on the paper
out feed and all is working now but i found an other problem 2/3 of the
page printed have dark line spaced by 7.5 inch. Al the kind of test
using the pc or the internal test of the printer show the same line.
It's not a clean sharp line it's 1/8 large darked in the center but
strait across the page and also apear some time at the botom/top of the
page outside the normal print area of the printer. Since the spacing
was a 7.5 inch i was sure it was not the toner but i decided to take it
apart and inspected the drum. clean no line. I put apart the printer
trying to find somewhere in the paper path somewhere that ad mark with
a spacing of 7.5 inch.

Only information i found said to Replace the laser/scanner assembly My
understanding of that kind of part similar failure would not give a so
precise patern?


Roar

 

[Steve Mackie]

out feed and all is working now but i found an other problem 2/3 of the

page printed have dark line spaced by 7.5 inch. Al the kind of test
using the pc or the internal test of the printer show the same line.
It's not a clean sharp line it's 1/8 large darked in the center but
strait across the page and also apear some time at the botom/top of the
page outside the normal print area of the printer. Since the spacing
was a 7.5 inch i was sure it was not the toner but i decided to take it
apart and inspected the drum. clean no line. I put apart the printer
trying to find somewhere in the paper path somewhere that ad mark with
a spacing of 7.5 inch.

A repetitive defect caused by the drum will produce the defect every 3.75".
Oddly enough, 3.75 x 2 = 7.5".

First thing I'd do is replace the toner.

Steve

 

[roar]

A repetitive defect caused by the drum will produce the defect every 3.75".
Oddly enough, 3.75 x 2 = 7.5".

First thing I'd do is replace the toner.

Steve

Thank's for your quick answer you are probably right, I didn't take
time to do my basic math (1.15 diameter drum = 3.75
Circumference). After playing to much with the toner i made a scratch
on the drum but at least that helped me to figure that the patern is
always in the same region on the drum and at that place the side on the
drum have some damadge outside the print area where toner make some
acumulation and probably lift the blade/(kind of wipper) inside the
cartidge and left to much toner i cleaned the excess and the following
page the mark was lighter and came back after few page (and the
accumulation also was back on the drum) now time to find a cheap toner
to test
My office look like a a HP museum of old printer in the last few month
i collected 6 "old" hp laser all non working got few back on track
with small investment older one (like 60 pound laserjet III) have no
value on market but i gave it for the price of the toner i bought and
to a student that cannot afford buying 50$ ink every few month for it's
inkjet

Michel

P.S.: Any one know where to buy used RG5-4248 DC Controller PCB Ass'y,
110V, LJ 2100 at good price or the electrical shematic of the power
supply side so i can rebuilt part that got burned by a drop liquid
(don't ask me how liquid got there ) 2 resistor and 2 diode have
burned and i cannot find the value to replace it