Epson SC P600 - Repair Issue- 2 year old printer

[Miss Cupcake]

Dear all,
My prints were suffering from banding so I did a head clean. Still banding and the nozzle check showed no colour in the LK black but good in all other colours including magenta. I use 3rd party inks. This LK black cartridge was empty, so refilled and still showing empty on the nozzle check. Performed a print head clean using rubbing alcohol and j-cloth under the print head for a few hours. Ran head clean again, still nothing with LK but now no ink from magenta either?
Just prior to this, the printer came up with message that my magenta ink wasnt epson which I ignored but now seems strange that after a few cleans to hopefully sort the LK, theres now ink printing in magenta.
I have had a repair man look at it, shook his head a few times at the use of 3rd party inks and said no amount of cleaning would ever sort it out and its needs a new motherboard: the Epson printer chips will ALWAYS eventually stop working with 3rd party inks. No telling when, but it will eventually happen causing this problem. A friend of mine whos been using 3rd party inks for years has ever had a problem and thinks my issue or more likely to be trapped air when the LK cartridge was empty and needs a flush through. Any advice please?

 

[Shadowman]

First lesson, never let an authorized Epson repair person see your workaround (3rd party inks) even if the printer is no longer under warranty, not that I'm advocating using the use of, but like any other service you've invited yourself to a more expensive repair. Not sure if using 3rd party inks will harm the motherboard but it could definitely affect the printheads. Try your friends suggestion and also look for any error messages that display on your LCD, the error codes will give a better indication of any particular issues for specific parts of the printer.