If your HP B210a has a clogged printhead, this guide will '''potentially''' resolve the problem and get the printer working again. I do not guarantee this will fix your printer, but if the printer is already doing this it's at least worth trying before you recycle the printer or resort to more drastic measures.
This guide is primarily made for the HP B210a, but can be used on similar HP 564 printers. Newer printers that use the HP 564 ink tanks will probably need to be partially disassembled but the core cleaning technique can be carried over. 4 or 5 color also does not matter.
On models I have not personally tested, I cannot guarantee the bypass will work on your particular model of printer. As long as you follow it word for word, you will probably be fine, however.
I have validated this method on 4 models over time. The method used in this guide works on the following models:
* Photosmart C6380
* Photosmart Premium C309g
* Photosmart Plus B209a
* Photosmart Plus B210a
'''Models which will become bricks if you bypass the alignment wrong'''
* Photosmart 6520 (Permanent printhead; Requires SETUP cartridges that came with the printer?)
'''Setting/crushing your expectations:''' Will this work every time? No. Some printers cannot be saved by gentle means and will need to be dealt with using more intensive methods. Try this and see if you want, but you will have to come to terms that this may not work. On more troublesome clogs, the issue may be terminal.