400h: Volume works once after reconnecting battery, no volume after that.

[Raghu11]

I bought a used 2008 400h recently. It has Mark Levinson audio. I replaced the factory stereo with Sony XAV100 head unit with CarPlay. Everything was working fine.

Last week the battery died. I jump started couple of times and then replaced the battery. The problem is that there is no volume. Tried radio, bluetooth, CarPlay, usb etc. 
The strange thing is, if I disconnect the battery and then connect it, it works fine until next time. But when I stop the car and start again next time, there is no volume.

What could be wrong?

I followed excellent advice in post by @Mamoon here : https://us.lexusownersclub.com/forums/topic/66814-no-sound/ 
I have checked the fuses and they are ok.
The fact that it works every time after reconnecting battery might indicate connections are ok.

[RX400h]

Did you contact a Sony representative? This is what I would do.

[Raghu11]

I doubt if this is related to Sony. I can connect the original stereo back and and I think most likely the result is the same. 

Regd working once after reconnecting the battery: It happens if the leave the battery disconnected for couple of minutes before reconnecting.

I checked the 'System Check' it shows 'NCON'. This happens even when the volume is on (first after re connecting battery).
The picture below shows AUDIO also 'NCON', I think that is because of aftermarket stereo.

 

[RX400h]

I don't think that there are many possible causes left. Did you actually try installing the original stereo to confirm?

[Raghu11]

@RX400h, I haven’t tried yet, but will do. 
can we say the Amp is fine since it plays volume at least the first time after reconnecting battery? 

[RX400h]

The clue may be that you jump-started the battery a couple of times. This could've caused something within your head unit to be flaky. If the OEM works perfectly after reinstall, I can't think of anything else it could be.

 

[simonp]

On 8/31/2020 at 9:18 PM, Raghu11 said:

I bought a used 2008 400h recently. It has Mark Levinson audio. I replaced the factory stereo with Sony XAV100 head unit with CarPlay. Everything was working fine.

Last week the battery died. I jump started couple of times and then replaced the battery. The problem is that there is no volume. Tried radio, bluetooth, CarPlay, usb etc. 
The strange thing is, if I disconnect the battery and then connect it, it works fine until next time. But when I stop the car and start again next time, there is no volume.

What could be wrong?

I followed excellent advice in post by @Mamoon here : https://us.lexusownersclub.com/forums/topic/66814-no-sound/ 
I have checked the fuses and they are ok.
The fact that it works every time after reconnecting battery might indicate connections are ok.

Long short since it was 3 years ago but I'm having the exact same issue. Battery died when i was on holiday, came back to jump start it and the sound from the aftermarket head unit only works on the first turn of the key. The sound has never worked ever since, until I disconnect and reconnect the battery again (sound works one time again) so I'm sure the speakers and connections are fine, checked the fuses which are fine also.