Dell S300W stuck in 16-bits color mode

Hello

The projector is all of a sudden showing picture in 16 bit (thousands) color mode instead of full 32-bit millions of colors mode.

It does this across all inputs (VGA. HDMI) and across sources (DVD, iPad, PC). So it does not seem dependent of source input.

I have tried everything: Resetting projector via menu, flashing and upgrading Firmware via usb, and all possible settings combinations. Nothing... stuck in 16 bits color mode.

Any advice on what I could do? 

I would like to try to do a full hardware reset. Any advice and how to do this?

If fact I noticed that even when upgarding firmware does not do a full real system reset as the total number of projector working hours is not reset.

Many thanks