| Title: | PrintServer_Hardware |
| Moderator: | CSCMA::SMITH |
| Created: | Fri Aug 23 1991 |
| Last Modified: | Mon Jun 02 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 487 |
| Total number of notes: | 1804 |
Hello,
I've got an LPS40 which prints great when its first turned on
and cool, however when it has been on for more than 2-3 hours it begins
to print with a dark background. It seems to be better when I clean
the corona wires and even the 50/100k replacement parts help for
awhile, but it quickly returns to printing that background. Also the
background seems be more concentrated on bottom (left side as it comes
out of the printer) of the paper. Also the print is fine. Also
the background is on the entire page, i.e. outside the normal print
area. Also the background has streaks that go down the paper, like
what you would expect from a fusing roller. I've changed print
drum and that is not it. I would suspect the temp control in the
fusing unit is not working, keeping the unit too hot, but I do not
have the temp strips as defined in the maint manual. Maybe I should
replace the fusing unit?
Anyone have thoughts on this problem, other than deep6 the unit?
A great many thanks,
Bruce.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 473.1 | CSCMA::SMITH | Fri Jan 31 1997 09:46 | 26 | ||
The Fuser can't put on more toner than what is there, I would suspect a
bias connection problem or a low laser problem. Since the bias changes
with temp, it is more likely, but bias and laser interact.
To check that the bias contact is good, you need door interlocks in.
First check the bias in the back by turning on switch 6, dps 205 on the
sequence controller. Take your DC measurement at the black power pack
on the lower left, put your probe in the left connection labeled 'b'
and measure to ground. You are likely to get a reading of 250 to 300+
depending on the temp of the machine this tells us bias is being sent
to the developer. Now go to the front of the machine. Find a
small protected pin on the lower left of the developer unit. It is
ususally painted red, green, blue or whatever and it pops through the
black plastic disk attached to the drum plate when you put the plate
on. Measure from this to ground, with the switch still on in the back.
you should get the same reading +/- 5v. If you don't get anything,
your developer contacts bias cover is probably broken. See this part
in the IPB Figure 22, sheet 2 of 2, item #71 (29-29888-01). The
'hooklike' contact on the back of the developer make contact with the
bias terminal in back, the hook may be bent or the bias cover may be
broken and the bias terminal is flopping around loose.
Well, there are of course other things that could cause the problem,
this one is most likely and easy to check, maybe you could call into
the support center 1-800-525-7104 and talk to Bob or Tom or me.
Sharon
| |||||
| 473.2 | PAMSIC::STEPHENS | Fri Jan 31 1997 13:50 | 3 | ||
Thank you for your kind and detailed reply.
I will check the measurement and report back.
Bruce.
| |||||