Hi everyone,

New member here. I have recently bought and installed an Android media unit which replaces the existing MMI screen. The unit comes with it's own cable harness so no cable splicing was needed. After installation, the unit itself works great but the original symphony unit appears completely dead - the lights on the unit do not light up. As a result, there's no audio coming through and I can't access any of the original setting menus. 

What I have tried so far: 

• Replacing everything back to stock - the unit still has no power
• Checked all the fuses, including the one on the back of symphony. All of them are good
• Check that 12V is coming to symphony 
• Checked for continuity between CAN gateway and CAN+ and CAN+ cables at the head 

I'm not sure what else to try next apart from buying a replacement symphony unit. Does anyone have any suggestions what could it be? 

 

Thanks!

You've do e a good amount of diagnoses. You could always look at a diagnostic check to see if any fault codes flag up. 

Thanks Steve, I should have access to Vag com from next week so will be able to do a proper scan. At the moment, I only have cheap elm327 module and it didn't want to connect to my phone this morning

Friday,11,February,2022,12:56:28:00009
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 21.9.0.2 (x64)
Data version: 20210903 DS330.0
www.Ross-Tech.com


VIN: WAUZZZ8K29A149523   License Plate: PK58KDX


                Address 56: Radio       Labels: 8Tx-035-1xx-56.clb
Control Module Part Number: 8T2 035 195 H    HW: 8T2 035 195 H
  Component and/or Version: Symphony3     H02 0210
           Software Coding: 0502008001010D004359070000
            Work Shop Code: WSC 06325 000 00000
                      VCID: 3D718CF3A471A7616A-8068
1 Fault Found:

02259 - Information Display and Control Head (Front) (J685) 
            011 - Open Circuit
             Freeze Frame:
                    Fault Status: 01101011
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 217
                    Mileage: 145958 km
                    Time Indication: 0
                    Date: 2008.06.07
                    Time: 22:20:38

 

Just did a scan on VCDS, this is the code that persists. Mentions of this code on Google mention that it's related ot the power to MMI screen. I guess I'll have to check all the cables over the weekend. What seems a little strange though is that the display test and sound tests options on VCDS both worked completely fine.. 

Hmm how odd. Did you reset the mmi at all? Definitely check the cables. But could be the screen.