What is BD mirror - Canon CLC 1120 Color Copier

https://evaly.com.bd/products/baseus-hd-convex-blind-spot-auto-rearview-car-mirror-silver-8458491

It is a problem with the LASER unit BD(Beam Detection) mirror. Check the BD mirror connection for any loose connection. if the problem remains, replace the Image Processor board.

You can't use a blu-ray player for mirroring.

I Has the same problem with my BD player and solved it by cleaning the optics. Its a quit tricky procedure because you have to remove the back cover of the optics system. Be carefull when removig that you first ground the optics as discribed in the service manual. then dismantel the optics and remove the 2 screws from the backcover. And use a small knife to lift the backcover. After doing this all mirrors and prismas are visible and can be cleaned with a qtip or soft paper.

it is related to laser unit BD mirror , replace your laser unit.

it is related to laser unit BD mirror problem. you have to replace laser unit.

Clean the Primary corona and BD mirror then clear error code.

The DMD bd has failed and needs to be replaced by a trained Samsung tech

Well here's the scoop. White spots mean that the mirrors are stuck "on" reflecting light. Black spots mean that other mirrors are not actuating and are not reflecting light. In any case the DMD bs or the DMD chip needs to be replaced by a trained Samsung tech only.
The DMD bd controls the DMD chip.

Have several problems with either a bad LVDS cable from Main unit to the LCD controll bd. Sometimes the cable is just not connected properly. If you reseat this cable and the problem still exists you most likely have a bad LCD control bd.