Pixma 5150 Error B200

[Aleksandar84]

Here's the story. Went out of black ink. Took the pigment black ink cartridge out, started refilling it, but noticed that 2/3 of the square area of the bottom sponge remained bone dry even after refilling it, the last third was soaking with ink. Put a few drops of ink on the bottom sponge just to "soak it" (probably not the best idea), wiped off the excess, and put the cartridge inside the printer. After reinstallment the Error 200 message appeared on the printer display. Tried taking the printhead off and cleaning it, tried the trick with manually moving the print head to the center while the printer is off and then turning it on, to no avail...
Any ideas?

Thanks,

Aleksandar