Black Ink Doesn't Print - Canon S750 Printer

Hi,

I've 'inherited' a Canon S750 printer.

For some reason, the black ink cartridge won't print to the paper. I've changed all of the empty print cartridges and replaced them with new ones. A new cartridge shows no change in printing.

The color cartridges seem to print fine. I've performed deep cleanings, print alignments and nozzle checks and nothing seems to resolve the problem. I've examined the contact between the head or jet or well and the cartridge. There doesn't appear to be a clog.

Does anyone have a suggestion?

Thanks,

BPer
Win XP