Officejet Pro 8600 Printing Black streaks

If you have changed a number of parts already, the printer may have a mechanical misalignment. I have an HP 8500 here that prints fine, for example.

Try this:

Open the HP Printer Software and select Maintenance Tasks under the Printer Actions heading. Go through the 4 maintenance procedures (HP 8500 screen) and run them all. This includes alignment and cleaning.

If after maintenance, the problem continues, then the printer needs service.

... Thinkpads_User

Hi;

Interestingly it prints some copies perfectly then goes back to printing faded.

You said you changed the printheads (two of these and these are not ink cartridges). So if the printer is mechanically OK (may not be at this point), try replacing the Black Cartridge and then set to print in Black only. Does that work. You may need the printer serviced.

.... Thinkpads_User

Hi;

I have ran a service on the Print heads and physically cleaned both sets of contacts, and confirmed that the nozzles on the cartridge are cleared. Of course this was not really necessary as the printer prints perfectly fine at times.

Still no improvement.

So then:
1. Did you try a new Black cartridge?
2. Did you run the alignment? (I assume "ran a service" means yes)

It is probably time to get the printer serviced as it is probably going out of alignment or the rollers are not even. In any event, this kind of defect cannot be fixed by regular software maintenance and cleaning.

... Thinkpads_User

>> Interestingly it prints some copies perfectly then goes back to printing faded.

For me in this case it seems like your toner / cartridge is running low, try to get a new one and try again.

The printer is an ink-jet printer and does not have toner. I have suggested twice now a new ink cartridge. @mavcom - any luck at all?

... Thinkpads_User

Getting a new cartridge today. Also I am going to clean the encoder strip.

Hi; what is the purpose of the encoder cable?

I cleaned that cable and it printed perfectly for about 7 sheets then when I tried again it went back to the ways it was.

The color prints perfectly.

I have since changed the black cartridge and it will only print the color section. Even if I set it to print in grey scale it prints the lines which are originally in color in perfect grey but those that were in black are not printed.

It is marked as an internal part, so you must have the printer apart. My HP 8500 does not appear to have such a part externally serviceable.

It does appear at this point that your printer needs professional printer service.  The hardware is a problem - not software, cartridges, alignment, or adjustment.

... Thinkpads_User

You may try to run the Self-Test Report :

Page 181 = http://h10032.www1.hp.com/ctg/Manual/c01643304.pdf

Page 184 might help too.

I think the self tests from the OfficeJet control panel were tried farther back.
.... Thinkpads_User

Yes I will take it apart today. as indicated earlier I was checking all the options before getting to that stage.

Ok, Based upon all of the reading I have done including contacting HP I am convinced it was the encoder cable. The client decided to get a new printer.

Thank you

Thank you, and I was pleased to work with you through this. .... Thinkpads_User