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car stereo head unit nasty distortion suddenly started happening for no reason
car stereo head unit nasty distortion suddenly started happening for no reason
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Old 15th May 2019, 04:06 AM   #11
Perry Babin is offline Perry Babin  United States
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Join Date: Nov 2003
Location: Louisiana
Does it do it on the radio (nothing else plugged in)?

Most people with this type of head unit use a USB flash drive or bluetooth. I'm sure your phone has Bluetooth. Why plug it in?

Are you using the same cable to plug into your phone/computer.
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Old 15th May 2019, 06:59 AM   #12
realflow100 is offline realflow100  United States
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it doesnt matter if i use the rear outputs bluetooth or USB or by 3.5mm aux cable in phone or computer. i tried all the ways and i cant stand bluetooth or usb flash drive. its just annoying to deal with. i prefer using cable cause i can just plug it into my pc or phone quickly and easily and bluetooth mode makes my speakers have a little bit more hiss when there is quiet sound playing. and also bluetooth mode is annoying too because it cuts in and out for like 0.1 of a second whenever there is a short pause in music or audio. overly aggressive standby in bluetooth stuff is why i generally dont like using bluetooth stuff. i prefer an always active signal
it always does the sound unless to change the balance all the way to the right. and it does the sound in both speakers

and it doesnt matter if i use the rear channels or front channels. same problem. i can have only the right speaker plugged in and it'll still do it if i have the balance set in the middle. but it stops if i change the balance to the right. whether a speaker is plugged into the left channel or not.

Last edited by realflow100; 15th May 2019 at 07:02 AM.
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Old 16th May 2019, 08:31 AM   #13
realflow100 is offline realflow100  United States
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does anyone know why it started doing this? im tearing my hair out trying to figure it out
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Old 16th May 2019, 08:51 AM   #14
cliffforrest is offline cliffforrest  United Kingdom
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Because it has an internal fault!

It needs opening up and testing / fault finding. Schematic, oscilloscope etc.

From what you have said so far, you do not have the knowledge to do this yourself, nor can it be done remotely.
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Old 16th May 2019, 11:56 PM   #15
realflow100 is offline realflow100  United States
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rip car stereo. would cost more to fix than just buy a new/better version because it would cost so much to buy the tools to diagnose the problem in the first place. not worth it unless it was a simple obvious fix like replacing an obviously visually burnt/broken faulty component but thats never the only problem.
i'll just see about getting a better amplifier off amazon or something when I can
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Old 23rd May 2019, 04:21 PM   #16
manlog is offline manlog
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Quote:
Originally Posted by realflow100 View Post
does anyone know why it started doing this? im tearing my hair out trying to figure it out
Hi,
maybe my suggestion coming too late.. : why not check the balance potentiometer!
it could have internal rails broken or dirty with conductive material.. this causing shorting signal at a certain path point... "being lucky" a pot spray lubricant could solve the problem!
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Old 23rd May 2019, 05:25 PM   #17
realflow100 is offline realflow100  United States
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There is no potentiometers in it at all. it has a single rotary knob on the front. Not a normal potentiometer. all the circuitry is microscopic surface mount stuff and really hard to even get to. it has a million screws holding the display PCB to the front plastic piece.
Ive looked all inside it and it looks absolutely spotlessly clean like it just came out of a clean room.
its gotta be a shorted out or partially broken/burnt component or chip somewhere that has failed in some way.

if I keep the voltage below 13v it doesnt do it hardly at all. but then i get less volume out of my speakers and more normal "distortion"
its so cheap it would cost more to buy circuit cleaner stuff and clean it off than to just buy a whole different/new amplifier or stereo.

Last edited by realflow100; 23rd May 2019 at 05:30 PM.
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Old 23rd May 2019, 07:01 PM   #18
manlog is offline manlog
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oh yes, now I've seen by google what it is on Dual manual.. it is a now-a-day "digital" machine (was thinking about a "vintage" one from an historical brand as Dual is..!), so pot is a "do it all" as by pressing and or touching etc... and of course smd parts inside...
-the lowering voltage supply effect you're referring makes think something bad in a zener diode or a voltage stabilizer, but of course service schematics are needed to troubleshoot problem... and maybe you're right about easier&cheaper look for a new one by a consumer brand.
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Old 23rd May 2019, 07:18 PM   #19
realflow100 is offline realflow100  United States
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Ive checked all what i can with my multimeter all the larger looking components and im not finding any strange readings on what I "can" check.

I also cant just bypass all the internal circuitry going to the amplifier chip because it requires so many support components to function.
I cant just solder some wires directly to apply power to the amplifier chip, bypass the mute function, and solder an aux cable as close to the chip as I can.
it would be way more trouble than its worth and im running out of soldering wire anyways i need to get some more soon.

my current idea is getting a set of these from amazon
Amazon.com: AOSHIKE 8-25V Dual Chanel HiFi TPA3116 Stereo Digital Audio Amplifier TPA3116D2 Class D Integrated Amp 2.0CH for Full Range Speakers Home Audio System 50Wx 2: Home Audio & Theater
and
Amazon.com: ALITOVE DC 24V 10A 240W Power Supply Adapter Transformer Switch AC 110V / 220V to DC 24V 10amp Universal Regulated Switching Converter for LED Strip Light CCTV Camera Security System Computer Project: Home Audio & Theater to power it.
unless someone can recommend me a similarly priced amp that outputs similar or more power as a single unit rather than requiring a seperate power supply.

Last edited by realflow100; 23rd May 2019 at 07:27 PM.
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Old 23rd May 2019, 07:47 PM   #20
miniman82 is offline miniman82  United States
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Could be 3 faults:

1. The 'jungle IC' (the large chip on the main board with all the audio handling functions in it) took a crap
2. The audio amplifier section blew.
3. Some sort of power supply problem, causing the audio circuitry to get all wonky. For example if the voltage regulation circuits inside aren't working correctly, they could be applying too much or not enough voltage to the internal parts of the board.

Either way it's likely not economical to repair, but if you really want to have a go at it you need an o-scope and DMM at a minimum to see where the signal inside it gets all jacked up. Most of the time you can read the part numbers off the individual chips to see what they are and what they do, just google that part number and pull up a data sheet. Once you figure out which one is involved in carrying the audio signal, you might be able to probe the output pins on it to see if it's providing clean audio. Same goes for the amplifier chip. Problem will be if you do find the problem, can you source a replacement? Sometimes chips are house marked and don't cross to anything you can order on the open market, meaning even if you identify the offending part you might not be able to get another one.

Good luck, I've fixed a couple HU's but the problem was obvious on those.
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