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Old 02-14-2021, 05:47 PM   #21
stj
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Default Re: brother hl3040cn color laser... output gone to worse :-(

one other thing, oposite the drum is usually a conductive foam covered roller - it needs to be clean
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Old 02-14-2021, 05:53 PM   #22
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Default Re: brother hl3040cn color laser... output gone to worse :-(

I was at work looking at the settings on our HP lasers when I posted earlier which offer quite a bit of control over density.
Give the toners a light shake side to side to see if it helps, the Magenta is quite pale also.
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Old 02-14-2021, 06:04 PM   #23
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Default Re: brother hl3040cn color laser... output gone to worse :-(

yes the magenta likely needs some attention (likely low / getting low). The conductive roller (transfer roller???) is with the toner cartridge, right? it is the roller that gets "biased", right? Trying to understand the "base density" that is automatically set by a new toner. If I understand, I could put in a new toner which would reset the bias voltage and then take it back out and put back the old, I should then see a difference with less density because the bias would be higher result in less toner pickup on the transfer roller. I will first try cleaning the transfer roller. Its not easy getting at the full roller without manually turning some of the gears which are "advantaged" so it takes a bit of effort.... at least that's what I have experienced so far.
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Old 02-15-2021, 03:36 AM   #24
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Default Re: brother hl3040cn color laser... output gone to worse :-(

the transfer roller is not usually in a cartridge, it goes on the other side of the paper
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Old 02-15-2021, 08:15 AM   #25
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Default Re: brother hl3040cn color laser... output gone to worse :-(

I am not clear on the terminology :-( The roller that is outward from the cartridge that "touches" the "exposure" drum (that has the optical sensors on it)... is that the "foam roller" that you refer to.... maybe referred to as the "development" roller.

It has a pretty uniform coating of toner across it in general when ever I have pulled the cartridge. Its not fully exposed without causing some gear movement on the cartridge which is very hard to cause as the gears are small and not exposed much to get at turning.

I have read some more from the service manual (thanks again). It indicates that if the bias voltage setting is reset to the initial value IF its a new cartridge (detected by the gear rib in the cartridge) is inserted and left there accordingly. IF a used cartridge is put in the bias voltage is reset but then is adjusted based on the amount / level of toner detected.
It appears that is done thru the "windowing" in the cartridge which appears to be somewhat "compromised" in some form (ie. not totally transparent). I might try some form of tape block to see if that changes the result any.

Last edited by budwich; 02-15-2021 at 08:17 AM..
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Old 02-15-2021, 09:21 AM   #26
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Default Re: brother hl3040cn color laser... output gone to worse :-(

the drum goes on the top of the paper,
the transfer roller is on the other side and charges the paper with static to hold the toner.
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Old 02-15-2021, 11:03 AM   #27
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Default Re: brother hl3040cn color laser... output gone to worse :-(

ok thanks for the further info. Blocking the windows with tape does not improve the situation. With more printing, it never getting a clean print and appears to be getting worse with each print of a simple text file. :-(

The density seems to be some of the issue in sections. I am waiting on a new toner cartridge (non-oem ... :-) of course). Will go from the result there in. thanks again for the posts / info.... the "magic" continues.
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Old 02-15-2021, 01:06 PM   #28
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Default Re: brother hl3040cn color laser... output gone to worse :-(

new toner cartridge didn't solve anything. :-( perhaps the drum has an issue. Attached is the printout from a plain black text file. Its about the same with either cartridge in the unit. Still not sure how the drum can be the problem if moving the pair to the cyan produces a much better result.... not perfect but better. I added the second picture of the same file printed with the black at the cyan position.
Attached Images
File Type: jpg hl3040cn newtoner.jpg (1.20 MB, 3 views)
File Type: jpg hl3040cn black in cyan.jpg (1.25 MB, 2 views)

Last edited by budwich; 02-15-2021 at 01:22 PM..
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Old 02-15-2021, 03:17 PM   #29
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Default Re: brother hl3040cn color laser... output gone to worse :-(

tried a 10 page print out of basic black text / diagrams. Attached, you can see the first page along with the 10th page. As you can see the "fog" seems to disappear as the pages are printed. This is somewhat how this whole thread was started in that the first page (of the day or so) would have "fog", worse than what is currently showing. Then, if you reprinted even the same page or other pages, in most cases they would print fine / good. These were printed with old toner as the new one did not seem to produce any difference / improvement so I thought I would "shelve it" for now.
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File Type: jpg hl3040cn 10 page.jpg (1.40 MB, 4 views)
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Old 02-16-2021, 05:05 AM   #30
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Default Re: brother hl3040cn color laser... output gone to worse :-(

i wonder if it's a problem with the high voltage generation - a bad cap or solder joint maybe
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Old 02-16-2021, 06:38 AM   #31
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Default Re: brother hl3040cn color laser... output gone to worse :-(

could be a combination of both maybe... kind of like a ballast and tube problem where a weak tube stresses the ballast such that the overall result in marginal / not dependable. Perhaps the charge roller (and connection) has a bit more impedance and the HV circuit can't produce enough "juice" to overcome. I have to look to see if there is a common HV circuit or individual ones.

I guess my next (and last) bet at this point might be a drum replacement to see if that improves things. I hate throwing parts at issues unknowningly.

Last edited by budwich; 02-16-2021 at 07:18 AM..
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Old 02-16-2021, 07:52 AM   #32
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Default Re: brother hl3040cn color laser... output gone to worse :-(

i just get old HP stuff from the local uni and strip & rebuild them.
the older (pre-feorina) stuff lasts forever if you clean it every 100,000 miles or sheets!
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Old 02-16-2021, 08:01 AM   #33
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Default Re: brother hl3040cn color laser... output gone to worse :-(

this was a replacement for my old monochrome but it hasn't been good. I am not really into collecting / reworking although, at this point, I am stuck between two points, give up and cycle for parts (limited) or get it working and recover something. thanks for yours and others comments along the way.
I need to continue reading thru the SM. There are some maintenance functions that might help and / or eliminate certain areas.

Last edited by budwich; 02-16-2021 at 08:02 AM..
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Old 02-16-2021, 02:27 PM   #34
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Default Re: brother hl3040cn color laser... output gone to worse :-(

IF I knew what I was doing, I would be dangerous... :-)

In the maintenance mode, there are a number of functions / status / checks. Mode 80 provides a summary list of the status parameters in the printer (ie. drum turns, prints, etc). It also has an set of voltages listed for the density bias for each drum. When I first looked at it, the voltage were something like 460,460,480, 440 (C,M,Y,K) which seemed relatively OK... although it appears to indicate a "weak black". There is a maintenance mode to check the density sensor and then run color density test. I did these and the numbers changed a bit 350,456,414,350.... it didn't help with the "fog" on the left side but it is getting a bit less with more printing... at this rate, I should be able to exhaust both my paper supply and toners before resolving this... :-)))

I also tried to do a meter check on the contacts of the drum but could get any impedance readings for any combination of pins. I was hoping to compare something across drum units for a possible clue. I guess like a fluorescent tube, you aren't going to get much of reading.

I will likely try a "reman drum" and cross my fingers that it is clears things up.
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Old 02-18-2021, 04:07 PM   #35
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Default Re: brother hl3040cn color laser... output gone to worse :-(

I got a new reman drum in for the black. It has corrected the "fogging" even on first print although a test of tomorrow might be the confirmation. Thanks for the hints, comments and SM as I have never looked at the guts of a laser printer before and the help kept me from floundering too much.
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