Based on your order history, I assume you're using a 7800/9800 printer model- correct?
Although we don't provide instructions or support for printer repair or replacing parts, etc... I can give you some feedback and suggestions based on my experience.
If NO ink is printing from any channel or flowing thru any channel when you do power clean cycles, then there's either a physical restriction (such as loose connection or pinch) or it could be electrical.
DON'T do any more cleaning cycles, or you could burn out your head since no ink is flowing thru it.
A few questions and my suggestion for moving forward:
1. How was the printer working before you replaced all these parts?
2. Did you make sure to connect everything tightly/correctly when installing the new pump cap assembly unit (esp elec. cable + make sure ink lines lead to the waste ink tank and aren't pinched)
3. Did the paper towel you had under the print head come out in one piece (and not leave a chunk on the print head)?
4. Was there any dripping or excess fluid when working on your printer? If so, it it possible the print head electronics got wet?
When I have replaced dampers in our x800/x880 printer models over the years, I make sure the o-ring is in place and end of the ink line is clean to fit straight into the damper point, then finger-tighten the plastic nut to connect the ink line (don't over-tighten with a wrench). It's important that the dampers fit well on the print head, and all screws go in smoothly- if screws or nuts don't tighten easily, then the pieces aren't together correctly and need to be taken apart/put together correctly.
I recommend taking the damper unit (black plastic that holds all 8 dampers together) off the print head. I only remove the top metal panel from the printer when replacing dampers or cleaning a head (not the whole side cover like the repair manual instructs you to do). Raise/unlock both cartridge locking levers to stop ink flow before starting. With the head moved to around the center of the printer, place a paper towel draped below the head/damper unit over the ink lines (to catch ink that may drip from the dampers when disconnected from the head). Unscrew the two side screws that hold the damper box onto the print head, and carefully pull the damper unit off the print head. With the damper unit over the paper towel, look at the side of the dampers to see if you can see any ink inside, then lower/lock the cartridge locking levers to open ink flow and see if ink starts dripping from the dampers (if it does, raise/unlock the levers again to stop ink flow). If ink doesn't easily flow/drip from the dampers, then use a syringe to check flow thru the line by closing one side cartridge lever, insert the syringe tip into the end of the damper and gently pull the syringe plunger to draw ink thru. If ink flows thru the line and damper well, then the problem isn't there, and is in the head or connection to the head.
I hope this helps, and you're able to get your printer working well again.