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Sony CDX-GT35U issue

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Anonymous user -  
STARGATE43 Posted messages 13754 Registration date   Status Contributor Last intervention   -
Hello,

I am here to share my problem because after a week of thinking, I cannot find any solution.

I have a Sony CDX-GT35U with an Oxygen amp (I can't remember the model, I will edit this message when I go back to my car), a 400(?)W RMS MTX subwoofer, Alpine speakers at the back and Sony at the front, installed in a 205 (original cables cut, and I put back an ISO plug)

At the beginning of last week, while everything had always worked very well before, my unit turned off when I powered it on (It displayed USB for a fraction of a second and then shut off completely, unable to turn it back on). I removed the unit and did a few checks (cables well connected, fuse still in place and in good condition, checked with a multimeter), I thought, oh no, my unit has died, so I went to Norauto to buy a new unit (urgent necessity..), once I got home I reconnected everything, but the new one does not work either. So I went back to ask them to test both. Great surprise, they work!

Back in the car, I just reconnect the unit, and this time it works! I try to connect the remote, and bam, the unit cuts off. I think, well, the amp is dead, good thing I have a backup one that was waiting to be sold, I will try it. Same thing. The unit cuts off when I connect the remote. So I try to take any cable (speaker cable) and connect the remote that way, just in case. Still nothing. I take my multimeter, I have current arriving at the input of the unit (the plug that connects to it), so the unit is still getting power! I connect a friend's unit, still nothing. After a few manipulations and another unit later, this last one works. I try to reconnect mine, still no power. I think this time, it's definitive; it's the unit. I go for a drive, and then my unit powers on, just like that. So I turn it on and try to get it to work properly, without the amp.
Everything seems to be working electrically, except that the sound is very low and distorts even at low volume.
However, I have not tried the remote connection that is at the back of the unit; I have always used the cable that is with the others (blue cable with a terminal).

I will try tomorrow with my friend's unit that did not want to turn on, and if it works, I will test my amp on it.

Quick summary for those who don't want to read my novel ^^ :

My unit cuts off when I try to connect the remote. I have tried other units, two amps, another cable as a remote, but each time the unit cuts off. Sometimes I have to wait hours before I can turn the unit back on. Now, the sound distorts at 1/5 of the unit's power. (4/5 before)

My questions are therefore:

Do you think my unit is definitely broken?
Do you think my amp is affected?
Can a remote cable alone mess up a setup like mine?
Could it be that I have an electrical fault that has appeared? Knowing that since this evening, my ventilation is either almost full or off. It seems like there is no dimmer (it may not be related) ^^
Is the remote connection at the back of the unit different from the blue cable?
Could this be coming from higher up in the car? (In the dashboard for example)
Even though I would be surprised that it moved without anyone touching it, could it be coming from the power supply of the amp or a bad ground?

Clarifications:
Yes, I am sure everything is correctly connected (checked by myself and a friend).
I have never had any issues with the unit or the amp before.
All my fuses are good.
I had a battery problem at the beginning of December, and the one who connected the clamps hooked them up backward (I was not looking at that moment), I had to replace the fuses of the amp and the unit but everything was functioning properly.

Thank you for reading and thanks in advance for your answers.

5 answers

  1.
    STARGATE43 Posted messages 13754 Registration date   Status Contributor Last intervention   2 648
     
    Hello, have you checked if your amplifier is properly grounded? Have you checked if the chassis of your amplifier is also properly grounded? It's possible that a positive terminal is slightly in contact with the ground of the amplifier.

    Have you checked that the + and - of the speakers are properly separated at the connections on the amplifier? Is there a capacitor between the battery and the amplifier? If so, check that it hasn't discharged too much after the battery change; if it has, it needs to be recharged.

    Does your battery still provide enough current to power everything? Check, with the engine running, the voltage should be between 12.8 Volts minimum and 14.8 Volts maximum, without the engine running for at least 1 hour, the minimum voltage should be 12.3 Volts or more.

    If the charging voltage is below 12.8 Volts at idle, accelerate a bit and see if it increases; if not, there is a charging problem with the alternator (regulator), likewise if the charge exceeds 14.8 Volts (bad regulator).

    Another tip to check if your battery is still good: leave the Voltmeter on the battery and start the car; the voltage should not drop below 8 Volts when the starter engages.

    All these factors can affect the operation of an amplifier; 2 or 3 Volts too low can impact its performance.

    If you have any questions, don't hesitate to ask.

    Best regards.

    --
    No problems, only solutions!!! :-)
    IF YOU FEEL YOUR PROBLEM IS RESOLVED, PLEASE MARK IT AS SUCH, THANK YOU.
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    1. Anonymous user
       
      Hello!

      First of all, thank you for your response.

      I have checked that my amp is properly grounded, which it has always been. However, I don't see how to check if the chassis of the amp is grounded. Should I set the multimeter to +12 on the amp and - on the chassis? If so, it's around 4V and then stabilizes at 0.

      Since I changed the amp, the stereo cuts out just with the stereo turned on and powered, so the speakers shouldn't be a factor, I think.
      I don't have a capacitor between the battery and the amp, just a fuse, and it is good.

      I'm at 12.8V with the engine off, having been stopped since midnight the day before (checked 20 minutes ago), 10V at the lowest at startup, and it runs at 14.50V at idle. So I think my battery and alternator are fine.

      What surprises me the most is that this problem appeared suddenly. I mean, I parked and everything was fine, then I came back to my car 4-5 hours later and that’s when the problem occurred.

      EDIT: I just reconnected my rear speakers, the sound is normal and doesn’t distort. Could I have damaged my speakers before?

      Equipment recap:

      Stereo: Sony CDX-GT35U
      Amp: Oxygen air² T330
      Front speakers: Sony Xplod XS F1325
      Rear speakers: Alpine SPG-17C2
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  2. kevin14789 Posted messages 1565 Registration date   Status Member Last intervention   394
     
    Hello, what's the reference for the post? I need the exact reference for the equipment.
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    1. Anonymous user
       
      Hi!
      What do you mean by the exact reference of the post? I provided it in the title.
      I gave the exact references of my equipment in the previous post.
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  3. kevin14789 Posted messages 1565 Registration date   Status Member Last intervention   394
     
    Sorry, I hadn't seen your post. It's not normal that you have 4 volts to measure the negative; you're taking it from the car's ground. What is the gauge of the power supply?
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    1. Anonymous user
       
      When I say that I have 4 volts, it's by touching the - of the multimeter on the casing of the amp, and it stabilizes at 0 afterwards. I'm not sure if it's the right place.
      On the ground of the amp, I have 12V, and when touching the spot where I connected my ground, I also have 12V.

      The power supply section?
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    2. kevin14789 Posted messages 1565 Registration date   Status Member Last intervention   394
       
      It's not the right place to connect to the amp's chassis. If you have 12 volts, that's good. Try to bridge the amp's positive terminal with a wire to the amp's remote.
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  4. STARGATE43 Posted messages 13754 Registration date   Status Contributor Last intervention   2 648
     
    To test the proper grounding of the amplifier's chassis, you need to set your tester to the Ohm (resistance) position. Then, connect one lead of the tester to the amplifier's chassis and the other lead to a ground point in the car. There should be a strong continuity; if the tester has a small sound indicator, it should beep loudly. If it does, it means the amplifier's chassis is properly grounded.

    If there is no sound indicator on the tester, the displayed value must be 0; there should be no resistance value between the amplifier's chassis and the car chassis or the battery ground.

    --
    No problems, only solutions!!! :-)
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    1. kevin14789 Posted messages 1565 Registration date   Status Member Last intervention   394
       
      If he manages to find 12 volts, there is a strong chance that his ground is good; he just needs to sand it if he hasn't done it yet.
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    2. STARGATE43 Posted messages 13754 Registration date   Status Contributor Last intervention   2 648
       
      Between the chassis of the amplifier and a positive terminal, there should be the same value as between the + and - terminals of the battery.
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    3. Anonymous user
       
      Well, well, I was at a friend's this afternoon, and we proceeded step by step:

      - Connected his unit alone without an amplifier, just with the front speakers: OK
      - Connected his unit with a different amplifier than mine and the front speakers: OK (Already a big positive point, it didn't work before)
      - Connected his unit with my amplifier and the front speakers: OK
      - Connected my unit with my amplifier and the front speakers: OK (Great surprise, frustration at the same time because we don't know where it's coming from)

      So my problem is resolved. We don't know exactly what happened. I think a cable must have been touching another one and messed everything up, without us seeing it, otherwise, I wouldn't have come to post here hehe. There's just some crackling and false contacts on the speakers, but that's just a detail, I'll fix that tomorrow.

      I just saw your response, so I haven't tested the casing resistance of the amplifier.

      Thanks for your help, guys! I had a slight doubt about the alternator/battery, now it's gone, thanks to your Stargate values. ;)
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  6. STARGATE43 Posted messages 13754 Registration date   Status Contributor Last intervention   2 648
     
    Well, that's good, that's all I can tell you, and no worries, it was my pleasure.

    Have a good evening and happy listening ;-)

    --
    No problems, only...solutions!!! :-)
    IF YOU FEEL YOUR PROBLEM IS RESOLVED, PLEASE MARK IT AS SUCH, THANK YOU.
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