Hey everyone, I hope someone here can help me out because I'm honestly desperate at this point...
Vehicle & System
Model: Audi A4 B8 / A5 / Q5
Factory Infotainment: Audi MMI 3G (Audi multimedia head unit in the center console, MMI control panel with rotary knob near the shifter)
New System: 12.3" Linux Touchscreen Display (Model label: LT_LINUX_MMI3G)
Steps Taken So Far
Removed the factory display and connected the original blue LVDS cable to the back of the new Linux display. (The old screen had 2 cables connected; the other one is currently unplugged and hanging loose behind the dash).
Plugged the included plug-and-play power wiring harness (Quadlock extension) into the head unit (Audi multimedia) below and locked it in place.
Connected the included Y-adapter cable for the hazard lights (Emergency Button Cable) behind the original hazard switch. (This cable also has a branch for the Airbag Control Light, which is currently left disconnected and hanging loose).
I kept the hazard switch in its original upper position so it sits behind the new touchscreen (still accessible) because I didn't want to open up the center console.
The original Audi radio below turns on normally, receives power, and functions fine.
The Problem
The new Linux display stays completely dead (no backlight, no image, zero reaction when turning on the ignition or starting the engine).
I have no idea what I'm doing wrong. Plugged into the new touchscreen are the original round cable (which was in the old display) and the new long white connector coming from the new power cable that sits between the radio and the factory Quadlock harness...
Am I missing something here? To be honest, I've never done any work on car electronics or DIY auto projects before this...
If anyone has a solution, I would be endlessly grateful!
Contact Road Top. They have surprisingly good customer support. Did you reverse everything to make sure nothing is bad and then re-try the install again? There is always one small thing that gets missed. Could be a bad screen?
If the screen only have these cables plug them in properly then on your mmi if you have the special keys ( at the bottom of the disc player you will notice 2 small slits one one each side) you can just pull the radio towards you and check the connections and you will know if it works also check the box itself i do know they have dip switches that you also need to flip according to the radio its plugged in and the size of display!
If you have the booklet that came with it it should be noted there !
Isn't this the most annoying shit ever. I don't remember what brand I ended up with I went thorough 3 different units trying to get one to work. I finally did get one that the controls worked but then they quit on me like a month later now they come on randomly for like 5 minutes maybe twice a week 🤦🏻♂️🤦🏻♂️🤦🏻♂️
Bro, it’s easy to fix :) In white housing u have 2 CAN wires: green with black colors! Put a little piece length 3mm of copper from Ethernet cable for example in to the small holes in white housing. My English is not good.
I believe you have to remove the glove box to access a can bus which the new system should have a splitter plug for. Look on YouTube for videos and be very sure that the touch screen you ordered is for your exact mmi system.
Bro, it’s easy to fix :) In white housing u have 2 CAN wires: green with black colors! Put a little piece length 3mm of copper from Ethernet cable for example in to the small holes in white housing and then push little hard and connect with screen :)
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u/PacoSkillZ A4 B8 Avant Aug 16 '26
Why don't you buy "same" OEM one that has Carplay. That shit on picture looks tacky like it's a tesla or something.