if you really feel it's electronic, The place to check is the ribbon cable's connection to the print head - making sure the silver connections are not bent (and if you remove it to check them that they don't go back in bent)
In my experience, this does not sound like an electronic issue, though.
I would do this (and since i'm not a certified tech, there's some stuff I do that others don't advocate, but has worked for me):
1. pop out the cyan cartridge and the 2 on either side. use a needle nose pliers to slip the tube syringe over the cyan nipple in the carriage. Then push some windex and / or cleaning solution through the nozzle. Make sure it doesn't drip into the head, then replace everything and do a few head cleanings to get the cyan back through the head.
2. put your finger over the air hole in the bulk ink bottle and squeeze. notice if any bubbles or air coming from the top of the bottle lids.