Stereo problems....

leighv · February 17, 2019

Just got back my SC430 after having the rear shocks, part of the exhaust replaced, etc, etc....

In short, I had installed a Grom Audio device, so that I could Bluetooth into the stereo, and play music from my phone, and make calls from my mobile.

It's worked, pretty well, until now...

In the past, the Grom sometimes was in limbo, and I had to restart the car if I wanted to hear the radio, cd player or the cassette (!!!)

I mention this, as the sound when it was in limbo, is similar to what I am now encountering.

Since getting the car back, I can't connect to the Grom, the sound from the radio, cd, (not tried the cassette) is the same as when it was in limbo.

Question: what could be the problem? The mechanic said that he had to take the the back end of the car off (my partner's words), to change the shocks, which would point to a problem/connection with the amp.

I've take the centre console out (as I did when I installed the Grom), and I can't see an issue, but any pointers would be appreciated.

Thanks.

Neil E · February 18, 2019

The mechanic would have taken the trim out of the boot to access the top mountings of the rear shocks. If there's no sound at all, then yes, it could be an issue with the amp or a connection to it.

leighv · March 8, 2019

So the mechanic has come back and said that he hasn't touched the amp - checked - and the fan on the amp isn't turning.

We've checked the 2 fuses - and they seem fine.

Therefore, I'm assuming that it's the amp that is faulty. But rather than buying another amp, is there a way to test it?

Just to be clear - there is sound coming from the radio and the cd, but it's muted.

All comments welcome.

Many thanks.

Neil E · March 8, 2019

Do the balance and fader controls work?

leighv · March 9, 2019

Yes - both do. Thanks.

The-Acre · March 9, 2019

I'm guessing you have the Mark Levinson system?

Neil E · March 9, 2019

Well that suggests the amp and the connection to it are okay.

To test the amp I would disconnect the Grom, put the connections back to standard and test the system.

leighv · April 8, 2019

So the stereo does work without the Grom attached, so I therefore assumed it was the Grom.

I purchased a newer version of the Grom, and have tested that - and while the stereo does work with the Grom attached, I can't get the Grom working. I've tested various cables, firmware, etc - and now Grom have come back to me and told me that it's the stereo, and that they can't help me any further.

Question: do you think the stereo is faulty, and what could be the fault that would prevent a Grom from working?

Thanks.

Neil E · April 8, 2019

Did you explain to Grom that the stereo works fine without the Grom attached?

leighv · April 15, 2019

I did, and this was their response.

Not necessarily, the port on the back of the stereo is designed for external accessory connections. This is common fault point on lexus and toyota vehicles whether it be a loss of power at one of the pins on the port or solder joints inside the pcb or the chips/circuits that translate communication from the externally connected device to the main processor of the stereo.

Neil E · April 15, 2019

What they are saying is true (though less so with the reliable SC430) but if the audio works perfectly without the Grom connected then there is no internal pcb fault or connection issue. The head unit and amp are working as they should.

Perhaps it's time to take it to a car audio shop. I'm sure any competent audio specialist will be able to work out quite quickly if there is a fault. (ASC Audio or Absolute Audio in Wiltshire look okay)

leighv · May 31, 2019

So I've tried both ASC (who said they wouldn't touch it), and Absolute, who referred me to Maple, who said they don't do repairs....

Any other ideas from anybody? Thanks.

leighv · June 10, 2019

Anybody please?

Neil E · June 10, 2019

Odd that neither Grom or anyone else can test the Grom unit itself. If no one is prepared to take it on and Grom aren't being very helpful, the only way to test it and the harness is to fit the Grom unit to another SC430 head unit to see if it works or not.

Does the audio (radio and CD) work perfectly without the Grom? Previously you said the sound was muted, as in not amplified, is this resolved?

Which model Grom unit and harness do you have, is it the USB3 connected to the CD port as per the diagram below?

leighv · June 11, 2019

Hi Neil - thanks for the reply. It's a USB2P and LEX harness. Thanks. Leigh.

leighv · June 17, 2019

Anybody? Thanks. Leigh.

Neil E · June 24, 2019

Hi Leigh, I'm not sure it will help but can you post some pics of the components and how it is installed?

If you can't trace the fault yourself then you just need to find someone who is prepared to test it and find the fault. If everything does work exactly as it should without the Grom connected then that points to the Grom or the harness being the issue.

There must be someone near you who would take a look at it.

Geoffers · June 24, 2019

Is it the lex cable that connects ion the back of the radio or the one that connects to the rear of the amp?

One is line level, the other is amplified as it switches on the speakers and the mute cable isn't always connected if the later. If it's connected, I wonder if it is hed high. Might be worth disconnecting - it is labelled on the Grom (assuming it hasn't been removed).

If you could do as Neil suggests and take a few pics of the harness and where it connects that will help.

leighv · June 25, 2019

Hi both. See pictures attached.

I've taken a picture of the harness and the back of the stereo. One of the two remaining ends plugs into the back of the stereo and the other to the cable that went into the back of the stereo.

https://gromaudio.com/installs/lexus-sc430-2006_-installation-of-grom-usb.html

Leigh.

Geoffers · June 25, 2019

Ah ok, it's using the line level inputs to the amp and the digital data lines for the info and selection when you select CD1/CD2 (depending which Grom you have).

I'm with Neil - it's not your system. It's a Grom cabling issue. I don't think it is a fault as such, I think a compatibility issue between the two. Don't worry about the fan not turning on the amp, its not always, only when the heat is too high on the output transistors.

Did you use the existing cable or a new cable with the new Grom? (I'm not sure if the connectors between Grom versions are the same). Is one the TOY version? I'm not sure what to suggest if Grom don't have any other cables to offer for your vehicle and that version of Grom. It's always worth another ask though. I'd take a look if I lived in your lovely part of the country.

I assume the info side of things works fine when you switch it in? If not, and a bit of a long shot on this, is it getting power to the Grom from the output of the headunit?

leighv · June 26, 2019

_{Hi - I actually tried my new cable and my new cable - but they are both labelled LEX - not TOY. The old Grom did work fine but with the LEX cable - but I assumed it was broke (and old) and hence why I bought the new version (and plus the new one has compatibility with the phone microphone. So based on the 2 don't work I naturally started to think that the problem was with the stereo.}

_{The stereo works fine - and all info is displayed. There is power to the Grom as I've update the firmware multiple times with different versions. Problem is that it just won't switch to the Grom. Thanks. Leigh.}