Brother MFC L8850 CDW strange solid color or blocks on copies and "toner error"

[tonerjockey]

Hello, at first i went to this for a burning smell. paper wrapped around the fuser film. cleared that and the film is worn and wrinkled. then i go to test and get the "Toner Error, one or more toner cartridges are not detected. pull out and reinsert all 4 toner cartridges."

i do that and then i get either a copy or print with a nearly solid full color background, or the top 2 inches are clean, then 2 1/2 inches is dark cyan shade, then 2 1/2 inches of purple shade and the last 4 inches is that full color greenish grey shade over the print or test pattern. in both cases, you can see the image being printed or copied, but with the heavy background as well.

and sometimes the prints are perfect. then the next heavy background.

then a "drum warning" to clean the corona wires.

i cleaned all the contacts for the toners, the drums, belt and cleaning unit. same. removed the HVPS PWB, an cleaned all the board contacts and the springs. no change. for the heck of it, since the customer had a set of reman toners i previously sent, i swapped them one by one. no change.

i found, that if i make a color copy, its perfect. if i make a black and white report print or copy, it is like it was, solid shaded.

I wanted to attach scans of the issue here, but not sure if a color scan will be to large a file?
the service manual shows a similar CQ defect, but they are calling it a wrinkle, so they aren't mentioning the paper with white at the top, then cyan, etc. or a solid process black where the printed image is still clearly visible.

i am thinking the HVPS may be the cause. the printer has under 13,000 total prints on it.

the service manual seems to list installing the firmware after the HVPS is replaced, which as written, sounds like a royal PITA.

does anyone have any advice if i can just swap out the board without doing firmware, or is it an easy procedure??


any assistance would be greatly appreciated.
thank you very much, Jim

[tsbservice]

I had one exactly the same minus it was time to change belt and drum. After parts changed I can't clear counters cause MFC was locked by admin and those counters are cleared ONLY in menu.
Problem remained even with new parts until I found the person to remove Settings Lock and clear counts then everything was perfect.
That said with only 13k counter I would try to clear Drum counter(and maybe Belt) and see how it goes.

[tonerjockey]

Good morning tsbservice, Happy Friday.
thank you for your input.
the issue here, is everything is intermittent to some degree.
that's why i am thinking the high voltage power supply. now obviously, if something is shorting, say in the drum, belt or cleaning box, then the power supply may collapse and drop its voltage and get this dark color all at once.

but the odd thing, with my testing, if i select "color" copy, its fine. if i select "black" it does this dark and error message.
and usually after the solid dark copy, even though i can see the image in the dark shading, it stops with the toner error.

do you know if i can replace the high voltage power supply board without having to enter new values, and do a firmware??

thank you very much.

[dalewb74]

if you suspect the high voltage, how you tried just using a different outlet? is it on any kind of surge protector or battery backup? those could be the issue as well. battery backup and laser copier = no bueno!!!

[tonerjockey]

if you suspect the high voltage, how you tried just using a different outlet? is it on any kind of surge protector or battery backup? those could be the issue as well. battery backup and laser copier = no bueno!!!

i thought it was strait into the wall.

[tsbservice]

Our was also intermittent. Just give it a try won't hurt to reset counters. Of course it may be high voltage board but I replaced close to zero of them on any Brother devices. And we have a tons of them

[tonerjockey]

i agree, I cant remember changing a Brother board. some i should have since my soldering is so pathetic now to replace the USB jack.
and this one has a total print count of 12856, so its not near a drum, belt or cleaner replacement.

they are thinking of moving to a new printer, so i will see what i can do.

thank you for the assistance. very much appreciated.

have a great weekend.

[dalewb74]

yeah the release date was 10 yrs ago this year. if it is very involved, i would push for the new copier.

[tonerjockey]

well for what its worth, i was surprised how easy i got that board out. the older Brother color laser MFC's were i thought a total pain to get the covers off and to what you needed inside. and weighed a ton.
and the customers say, "do you want to take it with you?" NO!!! as if.