The information is a bit incomplete. Is only the ink light on, or is
the power light also on? Any other LEDs lighted or blinking? When did
the problem occur for the first time?
I don't have access to the Photo 960 service manual, but the Photo 900
may be similar, and based upon it:
Likely causes are:
Bad cartridge (defective chip)
"Empty" cartridge (either) (or cartridge reading empty via the monitor)
Cartridge not set in place fully or correctly
Dirty chip or printer contacts
Printer contact wires bent or broken
3rd party cartridge with defective chip
The waste ink warning (at least with the Photo 900) shows as:
Power LED off and paper and ink LEDS blinking alternatively at .5 sec
intervals.
The program at the following web site may provide the EEPROM reset for
waste ink protection number, but I do not believe that is what your
printer is indicating.
http://www.ssclg.com/epsone.shtml
Art