my eight year old canon i860 suddenly stopped printing colors, deep black

I’ve deep cleaned it three times, tried to align the print heads, etc, to no avail. The orange light flashes 11 times which indicates the automatic print head alignment failed, due possibly to clogged print head nozzles. (The other two possibilities don’t check out.) Any ideas what to do next? Like to try manually aligning the print heads but don’t know how…