Hi All,

I "think" my amp might be finally dead. Its the non logic 7 Hardmon Kardon amp with subwoofer in the tailgate.

Symptoms are the following -

no audio - volume control makes no difference but does increase in number on the screen.
all fuses are ok
radio stations don't show their names either
I disconnected the battery for a few hours, and made no difference
I checked the fibre connection - and I can see red light on the cable, but no return red light coming from the amp itself.

When I disconnect the amp - the volume doesn't increment in number up/down, but starts working again once connected back.

I haven't checked voltage but thats my next port of call.

From reading the forum - I see the bluetooth module is mentioned a few times - is that further down the chain of connections and should I investigate that further ? or just pull the trigger on a 2nd hand amp from ebay.

so bumping my own thread here with more information.

I bought a amp off ebay - same type. 08 though vs my 07.

Anyway I've just wired it all in, and on initial power on - I could see red light coming from it. However once all connected up - same problem. No audio.

Can anyone advise what is the previous MOST/Fibre device in the chain, i.e. the one before the Amp, as that might be my problem.

further followup - I got a fibre optic loop plug. So I was able to loop off the Bluetooth module. Still no sound.

again - if anyone has a map or guide on the order the MOST devices are connected - it might help me rule out the issue.

OR

If someone knows of a suitable diagnostic tool to help me find the issue.

The only other thing in the loop is the colour LCD middle display.
Oh and the TMS traffic model in the boot

If the fibre isn’t working a LR logo will be stuck on the screen

What happens if you loop the amp out?
Does the 4x4 display work ok ?

Could also loop out TMS

Last edited by Andy K on Fri Jun 30 2023 5:52am. Edited 1 time in total

It does mention in the workshop manual about having to re-configure a replacement amp, however I don't know if this applies to just a new amp or a s/h ones as well as L/R are obviously not going to tell you that. Do you have any fault codes showing as there are a few listed for the AAM unless it's called something else in the earlier cars? which might give a clue.

Cheers
Col

Andy K wrote:

The only other thing in the loop is the colour LCD middle display.
Oh and the TMS traffic model in the boot

If the fibre isn’t working a LR logo will be stuck on the screen

What happens if you loop the amp out?
Does the 4x4 display work ok ?

Could also loop out TMS

So about 3 years back I replaced the Satnav screen with a Android unit - I used a fibre loop when installing to bypass issues then. I recently took apart all of that to confirm everything was connected up as per usual - and all was well. The audio for that comes out via the Aux on the headunit, it also doesn't produce any sound now though.

I will certainly try looping out anything and everything at this stage I do recall somewhere, but I can't find it now - was a layout of the order of the modules used. I was hoping someone might recall what is the module directly before the AMP.

Col wrote:

It does mention in the workshop manual about having to re-configure a replacement amp, however I don't know if this applies to just a new amp or a s/h ones as well as L/R are obviously not going to tell you that. Do you have any fault codes showing as there are a few listed for the AAM unless it's called something else in the earlier cars? which might give a clue.

If an ecu has failed the order of components doesn’t matter.

Order is only important if there is a break in the fibre cables.
A torch can be used to shine down the optics in the boot and see where /if it comes out white at the amp fibre

more follow up

I was out of country for awhile but back now trying to solve this. I took apart everything and confirmed all fibre is 100%. All fuses double checked and 100%. All wiring seems fine also. I can no confirm 2 new pieces of information that might help:

-CD audio actually works - never tested this originally because I dont use them anymore, but also never thought of it.
-I did the hard reset also - but to no avail
-finally I've noted the radio doesn't actually find a station to tune to, but also states to TA available.

So I'm wondering - since I've changed the amp already. In order of replacement - I'm thinking to buy a 2nd hand TMC off ebay (XRA500031) and see does that solve it. Next will be the bluetooth and then finally a headunit its a 6CD-565 model.

Any flaws in the above idea ? or anything obvious else I could try ? I've failed to get a scanner and my mechanic is not available.

Regarding the TMC and Bluetooth you can simply unplug the optic connector and bypass it either

a) buying a bypass loop off eBay £10
Or
b) pulling out the colour clip in the middle of the connector. Extracting one end of the fibre loop, and pointing it at the other end

Then see if you get tunes

I actually have a bypass fibre loop - so at lunch I tested bypassing both the TMC and then the Nokia bluetooth module. No difference in either case - music from CD continues to play and as each device was unplugged - on the radio - Phone removed appears briefly when unplugging either.

Only thing left to test - is the AUX 3.5mm jack - but I'm trying to find something to play through it ! all my phones don't have a jack anymore !

My gut is telling me - its the headunit thats fried in some fashion if it does infact house a tuner, that would explain its inability to tune anything in but its strange CDs play fine. Perhaps there is some refinement in there, that prevents boring static from playing on the radio.

doing a bit more research - I noticed an L322 has the tuner part seperate.



and flip that image upside down - it looks the same as what is attached to the L320 headunit

Click image to enlarge

If cds play music but radio doesn’t. It is either the headunit or the arial/amps in rear roof/or power to them

There are some coloured boxes above the rear side windows.
These are the amps for radio signal. Connected to side windows with a battery like connector

So I am back in business.

I purchased a used 6CD-565 that had a faulty LCD. It was a shade of grey - so I assume from a Disco.

It arrived this morning, and I was straight out after work to fit it - confirmed it worked. So I then swapped over my radio LCD/buttons etc onto the replacement unit. I finally have a radio back.

Thanks to Andy K for his patience in replying !

I can also confirm - the L322 radio module is identical in form factor however the actual board itself doesn't have the ribbon cable connections, everything elses matches however.

I now have a spare 6 cd changer part and an amp !

Grey ones were early versions.

Disco ones had rounded corners