C309g (CD055A) no black and other issues..

Question

Hey all..  Not sure which thing to post about first, so in random order, here goes....
I bought a used printer listed above in the subject..  It needed a new power supply, and ink, but seemed to be great.  I purchased the regular size cartridges except the black which they had in XL size.  I printed a total of 3 test pages (set up on three computers), I printed one 8x11 photo via bluetooth from my phone, and my wife printed 2 8x11 photo's from her PC.  All 3 8x11's were on regular paper.  Oh, and we printed one of the dots built-in pages..  So if you're counting (and I KNOW I am), that is a total of 7 pages.  Additionally there may have been one demo page (possibly a total of 8 pages, then!), can't remember if I did that demo page on the previous owners ink or if I did one on the new ink I bought (previous ink was old/empty).  Oh, and technically there was an alignment page, so final total 9 pages.  After those nine pages, my magenta and yellow ink were both down to around 65-75 percent.  It sat a week without use (literally, 7 days).  Today I went to print some regular text (black only) and it shot out at me blank pages.  I tried a few more times, and nothing but blank pages.  Tired of running back and forth, I printed a built-in "school paper" page or wide ruled paper (heh, how cool in a pinch is THAT feature!).  It printed perfectly - Course it's blue and magenta, no black..
So it's been awhile since I used inkjet, but I quickly rememberd the handy utility to clear/clean printheads.  Ran that.  It failed, assumedly for missing black (it had the gray'ish photo black, but not 'black' anywhere on the sheet.  After the cleaning failed, I removed the black, and all the colors.  Seems to be black in there (as should be!) I dabbed the bottom with a paper towel gently, it turned black...  So I put it in, and it whirred away doing it's thing to re-align, and then it told me the shocking news that my printer was low on ink, and showed all levels to be well, I suppose about 10-15 percent remaining (think SMALL skinny lines).  Now I know this is an estimate, but I'm concerned from the get-go that after only 9 pages it was down to 65%!! 
Before I found the forums, I found a site that recommended removing the ink cartridges, and removing the print head itself and soaking the bottom portion (up to the wire meshes, slightly covering them, but not the entire thing) for awhile in IPA (isopropal alcohol) and then dipping them in fresh a fresh batch to 'rinse' then gently hitting them with compressed air via air compressor (or canned air, I suppose, have an air compressor) to remove any debris and get the remaining alcohol off/out.  I then let it sit several hours to 'dry', which - it was probably ready immediately given the properties of IPA, but didn't want to chance it.. Re-inserted it and the ink, and.....  SAME THING. 
All the ink is official HP ink (since I'm sure that q is coming), was purchased from a big box retailer who ya all know and love or hate (no need to name drop)..  I'm wondering if...
1.  My ink, though coming out onto the paper towels could be bad/defective.  Given the really fast drop in the levels of ink, and the issue with black not seeming to print, seems possible? 
2.  Should I try the boiling the print head - err not boiling it, but sticking it in recentyl boiled water, and give that a try?  The guide that was posted here somewhere showed doing that, with IPA added to the water as an option.  Is it possible the IPA didn't break up whatever gunk might be blocking the black, that boiled water might break up?  Does that make sense, or would the IPA have broken it down? 
How do these print heads work exactly, or is that the big company secret?  I mean, is there a tube that goes for the inlet of black to the gold area underneath, cuz it's not directly under the gold like old fashioned cartridges used to be..  Is there any way to open up or access that area like, under the metal screens to get in there with a pipecleaner or something maybe, or something?
And, for bonus points (lol) Why does HP assign two names to their printers??  IE C309g (CD055A),  If my printer is the C309g, why is it ALSO the CD055A??  SO confusing and un-necessary..
Thanks for your time and patience

Answer 1

I've had a similar problem with black not printing, though my printer is a B8550. I bought new and have used it fairly lightly I'd say, but after only a couple of years it suddenly stopped printing the photo black (it has separate cartridges for black for photos and black for text, etc.).
   It prints on regular printer paper just fine using the other black--but not a drop prints of the Photo Black (yes, it's full). Since I've cleaned the print head, and even bought a new one, and a diagnostic print shows absolutely no trace of the photo black, I'm fairly sure the printer itself is at fault. It's sold as a 'Photosmart' printer, meaning it's intended to use to print photos--large format too--so without photo black it is a huge brick as far as I'm concerned.
    I've begun to notice from these forum posts that there is an issue with HP and black ink, or at least whatever controls black for photo papers in their inkjet printers. If I'm not mistaken both yours and mine use the 564 cartridges, so maybe that suggests a common factor in such printers that is the culprit. I suspect HP knows there is a problem, either with the hardware or firmware, and I wish they would do right by us.