Laser 500 color M551 Printing large black vertical streaks

[TaraConverse]

Since replacing the black printer cartridge in our laser printer on 8/22/17, we're noticing faint black vertical streaks down the paper, about 2 inches thick.  This issue seems to occur intermittently (not with every print job) but very frequently.  

I've gone through the steps suggested on the support site:

1. Print Cleaning Page

2. Print Quality Troubleshooting procedure

3. Removed the black cartridge and gently shaken it

However, the issue still persists.  The last suggestion is to replace the cartridge.  But this is a max capacity new cartridge that 80% full and cost close to $200.  I don't think replacing is the most economical solution.  

What other steps may I take to resovle this?

[davidzuts]

The toner cartridge is probably still the issue and you can test to make sure. Go to the administration and then the troubleshooting menu and find the item to disable cartridge check. When the printer is in this mode swap the black and the cyan toners and then peform a self test. If you still get black marks that will confirm the toner is the issue. If the toner is HO OEM then it comes with a warranty and return it to where you purchased for refund or exchange. If not HP OEM then you are at the mercy of the vendor that provided the toner. Economics have nothing to do with your issue. You either have a bad toner and need it replaced or have an issue with another item in which case you may need service. My money is on a bad toner.