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Strip Down Guide for BenQ 28" VA Monitor GC2870H



  • @adrien check out this forum thread. cruunnerr explains different methods on how to turn on/off your screen. He helped me setting up my system which uses a relay and PIR-sensor to power on/off my LCD. I think that’s what you’re looking for.



  • Well i’m not sure, i don’t use the magic mirror OS but home made application. I use a pir sensor, i would like to have instant poweron/poweroff without any OSD message on screen. So My question was if i cut the pin 3 or 4 on the backlight connector will it work ? To be clear when the PIR detect someone the relay connect the PIN (3 or 4) after few seconds relay disconnect the PIN (3 or 4)



  • @adrien That should still be possible with the script method described in 5.1. Instead of the power lines for the controller board of the LCD you use the cables that lead to your backlight.

    I don’t know what LCD you have. Some have an extra inverter or LED driver board. You can take the cables from there. Some have a 40 pin LVDS cable (instead of 30 pin), so you have to check the datasheet which wires are for the backlight. I’d take the VCC wire for the backlight, snip it and connect both lose ends to the relay. That should work.

    Keep in mind that with this method the LCD is always on, only the backlight is off.



  • Thanks for your help. I use the same model :BenQGC2870H. I would like to combine a solution where i have a minimum power consumption and fast without osd message boot.



  • @adrien Hi Adrien, that was my initial plan but I use the two relays now for my speakers to avoid the initial crack sound when powering on the amplifier und I use one relay for the monitor power supply and one for the amplifier.



  • @yep_dd Hello, and thanks for your guide 🙂 Did you try to do it ? do you confirm that could work ? Thanks



  • @Adrien No problem, I am pretty sure it should work but I have not tried it. I might in the future. I am working on a few other bugifxes as well (amplifier only turns on when sound is played and stuff like that). I also suggest to use the microwave / radar sensor instead of the PIR. it is much cleaner and can go behind the mirror.

    Regarding the OSD, instead of cutting wires to the backlight this seems like a valuable option. At the moment I can’t try this (I need a friend to help me take down the mirror as it is too heavy), but I will tomorrow: https://www.youtube.com/watch?v=y86AXOZwlgU (TL;DW: press menu button while turning monitor on and disable logo)



  • Interesting solution this is the hidden menu of the display. The problem is the boot time i feel like it takes a long time to boot no ? well i will also try to cut the wire if it doesn’t work properly i will solder them. About the microwave sensor i have a rcwl0516 to test but the problem is the range of detection it detect people from a very large range



  • @Adrien ah, okay I see… yes that might be a problem in my case it works just fine. I will see about the boot time tomorrow.



  • @adrien Okay, so it is about 3 seconds boot time I am estimating. No logo anymore. Just the annoying “HDMI1” screen on the lower right. Let’s see if that satisfies me or I will cut the wires as well. Have you tried yet?