hp 9000 cq problem

[Tom]

Anyone familiar with these machines ever had a problem with intermittent blank bands about an inch wide on the copies. Does it copying or printing, so problem has to be in the print section. It was low on toner anyway, so I replaced the toner/drum cartridge, no difference. I'm thinking some kind of electrical or ground problem, but I'm just not very familiar with this model. Also, bands appear in different places on the pages, sometimes 2 or 3, sometimes none at all

[blackcat4866]

Are these bands in the cross-feed direction? Do they repeat at any discernable interval, or do they seem to be random? =^..^=

[OMD-227]

I dont know about the insides of this model, but if its anything like other HP laserjet machines, and the cartridge is new/OK, I'd be checking the fuser.
If the upper heat roller is damaged or contaminated, you could be getting your black bands from there if they run in the paper feed direction. Previous pages could be contaminating the roller with toner buildup then depositing onto the follwing pages. If some of your pages are low coverage, the banding wouldn't be as bad as previous pages with higher coverage.

Otherwise.... got a sample page??

[prntrfxr]

9000 issues

I only have 2 records of banding on 9000's in my database.

Remember, this printer prints the paper in landscape on this one so it is important to know if the bands are in the direction of the long side (edge to edge) or short side (in the direction of print). Before you begin troubleshooting, clean the toner cavity (do not touch the transfer roller), transport/feed guide (plate right before fuser), & clean the cartridge contacts. Remove paper debris and dumped toner. Visually inspect the fuser rollers. Then begin with the following steps:

Troubleshooting Steps

1. Print the configuration page and stop the printer BEFORE it gets to the fuser (under the cartridge). If the bands are present, it isn't the fuser. If they are not, replace the fuser.
2. Print an engine test (engine test switch is on the DC Controller). This bypasses the formatter. If the problem does not exist, replace the formatter (formatter formats the image to be printer - very rare, but it is possible).
3. If the lines are edge to edge in the opposite direction of print and toner cartridge did not fix the problem, replace the DC Controller

Below is the history. Although, it may not help you much.

I had a client (technician) call me with banding issue after he replaced the DC Controller & Formatter to fix a 13.20 Error (notorious problem w/machine - parts must be replace simultaneously). Turns out he tested the unit with the top cover removed and there are holes in the frame that allowed light into the print area causing excessive exposure. Reinstalling the top cover fixed that one. The bands were wider than an inch and in the direction of print from short edge to short edge.

Other client called with banding along the edge of the paper. When I asked for a sample, he produced a page with tiny bubbles in the direction of print on the right side only. Turns out he had installed the HVPS wrong when he replaced the DC Controller.

[Tom]

Thanks for the replies. For those that asked, bands are edge to edge, not direction of print, on 8.5 x 11, not 8.5 x 11R. Problem is not in fuser. Bands are blank or very light & intermittent at that (3 or 4 out of every 10). This is a printer/copier, but it does it when printing also. Drum/toner cartridges is new, but same problem existed on the old one. Cleaned machine, including transfer roller assy & drum contacts. As I said in post, I'm inclined to think elect. problem as I've eliminated all the simple things. Printfxr is probably correct in that it is the DC controller, but I was hoping others had seen the problem before ordering such an expensive part. Does this mean the formatter need to be replaced at the same time? Machine is not giving a code, just intermittent blank bands.

[prntrfxr]

It is unlikely that it is the formatter. Try the engine test (a button on the dc controller, top left of the board, let's you perform this). If it happens when you do the engine test, it isn't the formatter.

You will be left with one of 2 options either DC Controller or HVPS. Let us know how it works out. DC controller is most likely of the 2.