4and3
Member Since: 30 Jul 2018
Location: Edmonton
Posts: 15
  
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| No red light on any MOST fibre optic cables |
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I have a problem with my 2008 D3 HSE with the logic7 audio. Having just picked up this truck, I was looking to tap into the aux connection for bluetooth audio streaming, as I do in my D4. The rear socket was destroyed, so I soldered a female 3.5 to the aux inputs at the rear of the head unit. Up to that point, everything worked okay.
Since then I have no audio, the screen has the Land Rover screen and the volume control, bass, treble etc, do not do anything. I can use the secret menu and unlock the screen, until the ignition is turned off, it then reverts to the LR screen.
So far, I have read through the forum and tried all suggested fixes. The only thing that seems odd is that none of the fibre optic connections has a red light. I have verified this at the head, bluetooth module, amp and Nav/DVD.
Where does the red light start, I have seen both the Nav/DVD unit or the head indicated. Can anyone confirm?
Any suggestions what to try next?
I am looking forward to becoming an active member of the forum and hope to learn and share as I maintain the D3 and 2011 D4.
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 30th Jul 2018 2:35 am |
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Adigorn
Member Since: 14 Mar 2010
Location: Birmingham
Posts: 546
 
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Hey i doubt you have no light at all, bear in mind the slave units only flash for a couple of seconds than stop, so you need to check the unit on start up. Your radio is the master - check it first. Especialy you are saying you were soldering the wires at the back of it ( nice work by the way  ) when you will be sure head unit is all OK and problem persist, use the MOST loop to diagnose the issue. All the best The Old rangies do not go mad, they mad go
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| 30th Jul 2018 7:05 am |
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4and3
Member Since: 30 Jul 2018
Location: Edmonton
Posts: 15
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Thanks, I will check the radio this evening. If it is working correctly, would the red light at the MOST connector, be permanently on, or just for a few seconds on startup? I did disconnect all wiring from the head unit before tapping into the aux inlet, but not discounting my handiwork as being the issue  In the event there is no red light at the radio, anything else to check before having the unit tested?
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| 30th Jul 2018 1:45 pm |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10684
 
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i recall the red light being on for a long time. You shouldn't miss it. (as soon as you unlock the car it should come on)
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| 30th Jul 2018 7:24 pm |
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Flack
Member Since: 06 Sep 2006
Location: Preston Lancashire
Posts: 6308
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As long as the ignition is on you should see the red light from the MOST, disconnect it from the back of the radio and check if you see it there first, if so you then need a MOST loop to check out all the other units that use it , that you have installed on your car..
Flack 
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| 30th Jul 2018 7:30 pm |
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4and3
Member Since: 30 Jul 2018
Location: Edmonton
Posts: 15
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Firstly, thank you for the input. I really appreciate it. Having just found this forum, I suspect I will be a frequent visitor and contributor with a D3 and a D4 to keep on the road.
There is no red light from the MOST port on the radio. Prior to removing the radio plugs and tapping into the aux input (since removed), everything worked. Could it be an issue with the larger wiring plug or is the MOST on a specific fuse?
I will see if I can find someone who can bench test the radio before deciding on next steps.
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| 31st Jul 2018 2:32 am |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10684
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open the radio again.
Follow the 2 optics to the connector. Are they still attached?
Power it up with the lid off. Do you see a red light near the PCB? If yes, you can find out where the break is.
Humm maybe I'm thinking of the LCD display, but the same should apply
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| 31st Jul 2018 11:10 am |
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4and3
Member Since: 30 Jul 2018
Location: Edmonton
Posts: 15
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Good idea. With the top cover off the radio, there is no light from the PCB and both optics appear connected to the board.
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| 31st Jul 2018 12:29 pm |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10684
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have you checked in the dark/garage? It's not massively bright on the PCB
If the headunit has power (front LCD on) then I guess you need a new headunit
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| 31st Jul 2018 5:39 pm |
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Flack
Member Since: 06 Sep 2006
Location: Preston Lancashire
Posts: 6308
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Have you checked the connectors for a pushed back pin, or even a broken wire. I cant see what you would have done to cause this if you just connected to the aux line. even if you wired it wrong it should just blow a fuse and not the whole unit.
Have you tried holding in both big buttons on the radio for 10 seconds or so..?
Flack
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| 31st Jul 2018 6:15 pm |
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4and3
Member Since: 30 Jul 2018
Location: Edmonton
Posts: 15
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I can't see what I did is the cause of the problem, but that could be wishful thinking 
Tonight I checked for a light on the PCB and did not see anything. I then checked all of the pins with a continuity checker with the plugs connected and battery disconnected. The only thing I am not sure about, on the larger plug (C1354) at pin 11, the brown and blue wire - battery voltage input, had continuity all over the radio casing. Is this normal with the battery disconnected?
I also connected my iid tool and had two error messages for the instrument pack: U0010-87(28) Medium speed CAN communication bus - bus signal/messaging failure - missing a message. Also, U0184-87(28) Lost communication with audio unit - bus signal/message failure - missing a message.
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| 1st Aug 2018 2:19 am |
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Flack
Member Since: 06 Sep 2006
Location: Preston Lancashire
Posts: 6308
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Those errors are because your MOST system is not working, on the large plug you should have two live feeds, one from the battery, and the other one from the infotainment relay from the bcm, are these two working .?
Flack
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| 1st Aug 2018 8:11 am |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10684
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Yeah on the large plug are 2 bigger terminals on the end.
These are + and - power. CHeck you have 12v across these.
I thought the blue? was an output from the head unit, to the infotainment relay, which powered up and rest of the system.
The radio also has CAN bus wires going into it.
Does sound like the unit is dead or lacking power.
I though you said the radio display was on though?
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| 1st Aug 2018 11:14 am |
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4and3
Member Since: 30 Jul 2018
Location: Edmonton
Posts: 15
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I have 12v between pin 11 +input and the ground wire pin 1.
With the wiring plug connected and battery disconnected, between pin 11 and the radio case, I have continuity when probing the wire. With the radio completely unplugged there is no continuity from pin 11 to the radio case. Is this normal?
The schematic shows pin 7 as an output to the infotainment relay. I will check what that is doing later and locate the infotainment relay.
There is a CAN bus input and output at the same plug. Any suggestions for testing these connections?
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| 1st Aug 2018 3:59 pm |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10684
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You won't "Find" the relay ! Don't bother looking! It's buried in the back of a £500 unit and has nothing to do with your fault. Your car drives now. Leave it alone  unless you want a paperweight
Also don't mess with the CAN wires. Nothing wrong with them.
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| 1st Aug 2018 4:51 pm |
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