Canon mg5750 printer problem

[#1]

I have the above printer. It's been fine for years but yesterday the black pigment started playing up. I did a nozzle check and it was only printing half of the check on that ink. I've attached a picture. I've done cleans and removed the print head to manually clean but no joy. It looks like a printer issue rather than a clog, as it's cutting off exactly half of the pattern. Anyone any ideas. I'm reluctant to buy a new head in case it's the printer board and heads are about £30 on eBay.

Edit. I can't seem to attach a file????

[#2]

@penfold 

I’ve been through this with one of these printers. I removed the head and soaked it in diluted isopropyl alcohol, then even the stuff neat. I cleaned the electrical contacts very carefully etc. without success. After checking the cost of a new print head I put the money towards an Epson Ecotank MFP.

[#3]

Thanks. 

The printer is a good few years old, but I hate waste. It's a shame a new head is almost the cost of a new printer and not guaranteed to fix the issues. 

Anyone any advice on a good mfp?? Must admit I do like canon.