What sounds like is going on is that you starved your print head and may have some clogged nozzles as well as a weak vacuum pull.
See, once you get to that point, you can't just put cleaning solution in and watch for dribbles in the waste tray. It needs to come pouring out.
I'd start by removing the side panel, and then unscrewing the capping station. It's got two hoses underneath that you need to remember how and where you took them from.
Inspect the little rubber trim ring around the capping station when it's completely out. If there's any ink build up, remove it, and check for little cracks or tears. Be careful with the capping station, if it appears to be in OK shape... because a new one is like $600, for that little bit of plastic.
Now inspect those little black hoses. By now, you would have noticed if they unplugged from the larger diameter clear hoses, and if there was a little plastic tube connector connecting the two. If there is a little hose barb connector thing, throw it in the basura! The black hoses will slide perfectly into the clear hoses with no leak. If you are so inclined, try and find something that will clean that little hose barb you are about to throw away. Unless you have needles around the shop, nothing short of super thin gauge wire will fit in there. That's a huge bottle neck, and I think it was installed on purpose to generate more on-site service calls. As it serves no real purpose other than to mess your printer up from time to time.
Anyway, back to the black little lines... these clog rather easily. However with your syringe, you might be able to flush fluid through them just fine, and think they are OK. They usually are not... squeeze between your fingers and you can feel they are hard. They clog much like artaries, and still allow tiny amounts of fluid to pass, but have little caked ink along the inside walls. Continue to mess with those until you are certain they are empty of little ink plugs.
Now you can flush fluid though the clear lines, and notice a lot of gunk build up there too... but these hoses are made of silicone and nothing really sticks to the sides once you send a few syringe pumps of cleaner through.
Now put everything back together and run a regular clean cycle a couple of times to try and re-prime the printhead. (You should probably leave the side cover off at this point until the printer is really printing again)
If it's still not printing, you've got printhead flow problems. For some reason, magenta is the one that goes bad first. hmm...
From this point on you need to be brave enough to pull your printhead off and give each fill port a good cleaning. However, a new printhead is $1200 and if you aren't comfortable in removing it, then don't. Just keep running the cleaning cycle and re-prime the printhead by using the printer's own pump.
After clearing out those lower hose lines, you should actually be nearly back to normal... my guess is that all the colors will eventually come back 99% - 100%, but you'll see what looks like clogged magenta nozzles that are missing. If that's the case still... you need to consider a sonic cleaning, or a new printhead. You can soak the print in a shallow bath of solution, and try to force solution though the tiny holes on the backside of the printhead, but it's tedious and hard to do. I actually shot cleaning solution straight into my eye once, because the syringe I was using wasn't pushed tightly up against the fill holes, and "FIIITTT!" shot straight back up into my eye. Luckily I was wearing contacts, and it didn't do any damage to my sensitive areas. Just stung for about an hour, even after I flushed it.
Anyway, back to the fix... yeah, just clean the hoses underneath and see what that gets you. Have some custom test squares set-up and ready to print. The usual, CMYK 100% values of each, Red, Greens, Oranges, Blues, Purples. That way when you start to print again, you can see what colors are lacking. Then, you determine if you need to fiddle with the print head.
Good luck.