DIAGNOSIS Support Code 1688 is a waste ink absorber pad error. The internal pad that soaks up waste ink from cleanings is near full.
FIX The pad needs resetting or replacing. You can try a service tool reset if you have the software, but this is a physical part. For long-term use, the waste ink absorber must be replaced.
IF THAT DIDN'T WORK The counter is locked. The printer will eventually refuse to print. You need a full service reset performed by a technician or with a specific service tool.
HEADS UP Ignoring this can cause ink to leak inside the printer, leading to electrical shorts. Address it promptly.