I have finally replaced the Epson D700 printer head and also the pump unites. The printer is now back to normal.
Over the weekend, I installed Window 10 updated. It gave me the following problems:
1. Communication to the printer via USB keeps breaking and I can no longer print;
2. Photoshop CC 2018 (Latest version) is half dead! I mean, it keeps crashing and gives strange errors. Also, Photoshop will hang for no reason.
To resolve the problems, I have now rolled back to my older version. So, my printer is now working again. I have not tested Photoshop. Should be ok.