Why does my projector display incorrect colors?

Optoma HD72, ~3 years old. Bulb has 1100 hours, of the rated 2–3K life; previously shown no adverse signs or symptoms of failure.

Migrated unit to different location with exceptional emphasis on gentle handling, cable disconnection/connection, mount removal and replacement. Upon repowering, the unit displays all input sources with very strange coloring, almost as if one of the RGB/YCbCr channels is very dimmed or non-functional. The brightness/contrast and overall image continues to display in viewable manner, but with a significantly purple/blue almost-inverted tint.

No configuration changes were made to the settings, nor were any source devices changed. All inputs (DVI, HDMI, component and composite) reveal this same color issue. Multiple video formats have been tested (DVD, SVCD, h.264, .ogg) over all source inputs. Each connection has been checked for proper seating, ‘wiggle’ tested and replaced with an alternate cable.

Bulb was visually inspected (ok) and reseated. No change.

A factory reset was performed on the output settings configuration. No change.

The unit is out of warranty and Optoma has not offered any significant troubleshooting ideas, apart from paying to send it in for diagnostic service. Any ideas for where to probe next, before cutting a check?