Car Headunit (Chinese?) No Sound / Audio

[Bloopeta]

Just bought a car that has a stereo in, thats bluetooth etc, and powers on fine and all functions seem to work, BUT there is no audio/sound.
I have tried another unit in the car that works fine, so know it definitely a problem with this unit.

I know it just cheap rubbish, probably of chinese origin, but its really bugging me just throwing it away and replacing it 🙈🤣

I know zero about things like this, ans its probably unfixable, or more trouble than its worth, but just wondered if there was anything to check, as what could lead to an easy-ish fix? Havnt opened it up as yet.

Any help or advice greatly appreciated.

Pics of the unit attached, although isnt alot to go on unfortunately.

[petehall347]

push a pin into the reset hole

[redwire]

not to be confused with the mic hole lol

[Bloopeta]

push a pin into the reset hole

Just tried that, did it for 1 second, 30 seconds, 60 seconds.... still no sound

[Bloopeta]

not to be confused with the mic hole lol

I found the right hole 🙈 had rst written near it

[Per Hansson]

Have you tried doing a basic test of the unit outside the car?
Connect ground and 12v then some speakers and see how it behaves?
Oh yea, and tried pressing the mute button and playing with the volume?

From the manual: each cable can not be grounded, can not be shared, can not touch the line, otherwise there will be no sound output, output sound distortion, machine fever and so on

Especially important that the machine can have a fever after a long flight: When you receive the product, please do not take it directly to the car for installation. Because the product is in the after a long journey, it may affect the product.

So if it doesn't work make it a nice cup of hot tea and give it a hot blanket and some bisquits

[jiroy]

It doesn't need to be a Chinese model or anything else . According to my long experience , it's usually a case of blown speakers , cut and bent speakers wires and even wrong wiring sometimes . Next to those frequent cases , comes primarily the Amplifier sound main chipset , easily blown in many systems due to speakers wiring shortage . Unfortunately , there are no fuses for that . The main amplifying chipset could be one (most of the times) or two , and it's always screwed to the large Alu. sink you see on the device's rear . If you don't have a source of 12 v 10 A. at least , you can always use any computer power supply .. just don't raise the volume too high .

[Bloopeta]

Have you tried doing a basic test of the unit outside the car?
Connect ground and 12v then some speakers and see how it behaves?
Oh yea, and tried pressing the mute button and playing with the volume?

From the manual: each cable can not be grounded, can not be shared, can not touch the line, otherwise there will be no sound output, output sound distortion, machine fever and so on

Especially important that the machine can have a fever after a long flight: When you receive the product, please do not take it directly to the car for installation. Because the product is in the after a long journey, it may affect the product.

So if it doesn't work make it a nice cup of hot tea and give it a hot blanket and some bisquits

Yeah I have tried it in a different car to eliminate it being the vehicle and speakers etc .
have also tried a different head unit in the vehicle it came from, and that plays fine.

[petehall347]

https://www.youtube.com/watch?v=1JbdWu4g4yo

[Bloopeta]

It doesn't need to be a Chinese model or anything else . According to my long experience , it's usually a case of blown speakers , cut and bent speakers wires and even wrong wiring sometimes . Next to those frequent cases , comes primarily the Amplifier sound main chipset , easily blown in many systems due to speakers wiring shortage . Unfortunately , there are no fuses for that . The main amplifying chipset could be one (most of the times) or two , and it's always screwed to the large Alu. sink you see on the device's rear . If you don't have a source of 12 v 10 A. at least , you can always use any computer power supply .. just don't raise the volume too high .

I thought it may be the case of something blown, oh well was worth a try

[Bloopeta]

https://www.youtube.com/watch?v=1JbdWu4g4yo

Thats the one, unfortunately Id already been through all the settings etc.

Given that video is 5 years old, Id guess that the unit is around that if not older.

Was worth a try, to try and get it going since everything else worked, but alas I am beaten lol

[Bloopeta]

Unfortunately its time for the scrap heap lol, thanks everyone who commented

[lotas]

In this place behind the radiator there is an audio frequency power amplifier chip, if it does not heat up (cold) when the device is operating, then just change it, it usually costs TDA7388..

[Per Hansson]

Unfortunately its time for the scrap heap lol, thanks everyone who commented

Not at all, this is the stage where the fun begins.
Or put more succinctly by a member of this bard: a working TV? How boring!

[redwire]

Have you tried doing a basic test of the unit outside the car?
[...] From the manual: each cable can not be grounded, can not be shared, can not touch the line, otherwise there will be no sound output, output sound distortion, machine fever and so on [...]

This is referring to the loudspeaker outputs, it uses a bridged amplifier configuration. Grounding any loudspeaker lead will blow the IC. Back in the day some speakers were grounded to the car chassis/door.

I'd keep going, take it part look inside. Bad soldering is also a common problem.

[Bloopeta]

This is what it looks like from the inside

[Bloopeta]

In this place behind the radiator there is an audio frequency power amplifier chip, if it does not heat up (cold) when the device is operating, then just change it, it usually costs TDA7388..

I have added a picture of the inside,

[lotas]

Unscrew the two bolts, remove the clamping bar and look at its body, it looks like burning underneath, the body may have exploded.

[Bloopeta]

Unscrew the two bolts, remove the clamping bar and look at its body, it looks like burning underneath, the body may have exploded.

I have done what you said, and yes it was black underneth.

I had a spare basic Citroen CD player, so I desoldered the part out of that, and soldered it into this unit.

It now has sound

Thankyou very much

[stj]

that chinese unit looks a lot better inside than the italien crap the car makers like to fit!