PDA

View Full Version : Bizhub C250 With Yellow Background - Changed IU & Laser


Custom Search


pajeroid
01-20-2010, 10:18 AM
Good morning,

Machine was installed 2nd hand and was fine - then started giving yellow background. Sometimes has white band in middle where all image appears normal. Changed Yellow Laser & Yellow IU to no affect.

I have attached a sample test print.

Also tried checking ribbon cable on printer control board & connections at rear.

Help! :confused:

mrwho
01-20-2010, 10:28 AM
Check the cable that connects the scanner unit to the main body for any bent pins. If all is okay, make sure you plug it in straight and not skewed, screwing each screw a little bit at a time.

mrwho
01-20-2010, 10:46 AM
If you're unlucky, it can also be a broken HV contact (the one that connects the IU to the HV board at the back (check this post of mine (http://www.copytechnet.com/forums/konica-minolta/24054-c250-black-background-2.html#post117541) to see what I'm talking about).

pajeroid
01-20-2010, 11:03 AM
Many thanks MrWho - I'm popping down to the customer this afternoon so will give this a try and report back. =)

fixthecopier
01-20-2010, 12:23 PM
I had a cf2002 do the same thing from only 1 computer in the office. After asking enough questions, I found that the computer had been upgraded to vista and was still using the xp drivers. My background was a stunning reddish orange with yellow spots.

SmellsHot
01-20-2010, 12:37 PM
Is that an internal print? Have you tried doing "initialize/stabilize" or any other process adjustments?

pajeroid
01-21-2010, 09:17 AM
* Update *

When I got to the customers the copies, prints and test pages were printing fine!

The machine was throwing a P8 code and the yellow was very faint so I exchanged the yellow IU and ran an initialize and stabilize and re-did all gradation adjustments 3 times.

The quality was then spot on! So its either an intermittent problem with a connection or something more weird.

SmellsHot
01-21-2010, 12:26 PM
Make sure your IDC sensors are clean as well......this can cause the P codes

pajeroid
01-21-2010, 05:29 PM
Yeah I cleaned them when I refurbed it but cleaned em' again on site yesterday so fingers crossed!

kmcopier
01-21-2010, 10:08 PM
replace your clutch for the transferbelt
9322 1300 21 page item 29 item 22.

pajeroid
01-22-2010, 09:07 AM
Its done it again this morning - why replace the registration clutch? I don't get it?

barratec
01-22-2010, 10:44 AM
I had something similar on a c250 but with magenta color. I fixed it changing the HV board.

copytechman
01-22-2010, 12:44 PM
Also double check that your drum ground is good and solid.. it can do something like that when it's iffy too... (drum ground is the silver tab just past the "PUSH" plate top dead center @ the front of the iu unit.)

Regards!
A.

907tec
01-22-2010, 07:56 PM
When I went to training for the 353 series, there was a machine exhibiting this same problem. Someone from a previous class had botched some procedure, resulting in a heavy yellow background on all printouts. The problem ended up being a ribbon cable. Im sorry to say that I dont remember exactly which one, but im guessing it was the PRCB cable. I do know that the cable looked fine on inspection, but the problem went away immediately after replacing it. Hope this helps.

pajeroid
02-03-2010, 09:31 AM
I had something similar on a c250 but with magenta color. I fixed it changing the HV board.

Well, we did this and the problem so far * touch wood * has stopped appearing, so many thanks Barratec. I'll add to your rep!

lrockett
12-28-2014, 12:35 PM
Same problem here, but in my case there is a yellow "layer" over all colors and objects covering the hole page including margins. Machine gives me status P-21 and sometimes P-8 and P-21. When I open the side cover there is yellow toner stucked on the belt. IU is new, about 10.000 copies. Machine status level 1 shows yellow TCR around 2% when the usual will be 7 or 8.

Itīs been raining here for a week and humidity is usually high. Always after a rainny weekend the machine behave strange. I already have this kind of erratic problems before and the cause looks always the same.

Iīve opened the machine and cleaned the two flat cable contacts and conectors with de-humidifying spray (donīt know how itīs called in english). Thats it, problem gone. Always when you face problems like this try the flat cables or contacts first. Only after that start changing parts.

Iīve done this procedure 2 or 3 times and always workes with spending any money with parts.

EarthKmTech
12-30-2014, 12:46 PM
The flat cable from the MFP board to the laser relay board is notorious for causing this problem. I presume you were talking about this cable.

Repeat offending machines can have the cable trimmed or replaced as a permanent solution.

peter@digitalswebsite.com
10-02-2015, 02:51 PM
Yes, clean sensors, could be a bent contact on the HV board on the back of the machine, not to hard to get to

Custom Search