Epson 7600 allignment issues
When aligning the blacks, it is easier to do it using the printer driver. After that you can align the rest of the colors using the printer control panel.
If you get nozzle deflection on the black nozzle it is possible that printing at 1440dpi will fix the problem but no matter what you do at lower resolution you will get banding. This is, of course assuming that the head is not slightly clogged.
If the nozzle check is perfect then it could be a mechanical problem.
For more details on how to troubleshoot banding problems that are not print-head related check the service manual. However, sometimes it is easier to make it worst.
7600 cartridges are easy to refill. Just get a syringe like these:
Cut the tip a little bit less than this:
You may want to use the syringe to remove the old OEM ink before refilling the carts with the new ink.
The weight of a full cart is around 385 grams but is not exactly the same for all colors. To be safe refill the carts once the levels drop to one start (about 20% left).
Don't forget to buy a chip resetter.