Related to the print quality:
There are several ways to improve the PQ (or to decrease it if the settings are not appropiate).
1. First I recommended to Align the printheads, in the image attached it seems that you have a lot of grain. It's caused if you remove the printheads and one time you reinstall again you don't perform one new alignment.

2. If the print quality is not improved, could you try with other kind of media (paper)?, What are you using in this case?

3. Check if the printheads are dirty, youo can do one recovery by front panel:
MENU > MAINTENANCE > CLEAN PRINTHEADS

4. If the print quality still being bad, check if the printheads are damaged, have you got any paper crash with this printheads? Could you compare the images printed with anothe VP485 and compare the results?

If the printquality of this printer remains bad, please let me now to troubleshoot the problem and evaluate the next level of actuation.

For more informations, please let us know here.