LS - 1st and 2nd Gen (1990-2000) Discussion topics related to the 1990 - 2000 Lexus LS400

No sound from Front Speakers - UCF20

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Old 01-05-21, 08:47 PM
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neonninja
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Default No sound from Front Speakers - UCF20

Hi all, since I bought my LS the front stage has not worked. I have the Pioneer HU. All rear speakers work fine inc the Sub. Fader is working as I can Fade to front and get no sound at all, then fade to back and it works.

Is this a common problem? If so, where do I start looking for the issue. I really want to retain the factory audio setup.

Thanks.
Old 01-05-21, 08:50 PM
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400fanboy
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Are the front tweeters out as well? The speakers mounted in the A-pillar of the door, next to the sideview mirror.

When I bought my LS, my driver front door speaker was dead as a doornail, and the front passenger was on it's way out. After 20 years it is not impossible that they've failed. Could you possibly ask the previous owner for more details on how they died? Were they both at once (electrical issue, speakers may be okay), or did they go at different times (natural speaker death).

FWIW I replaced all the speakers in my car and put a head unit in for bluetooth as a fix for my dead drivers door. Tape deck AUX was... pretty awful quality so I went all-in.
Old 01-05-21, 08:55 PM
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neonninja
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Yep the whole front stage isn't working. Previous owner bought it like this so couldn't provide any more detail.


Would it be possible its the Caps in the Amp? Would all 4 channels (2 woofers and 2 tweeters) be caused by a bad Cap?
Old 01-06-21, 12:51 AM
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heyTony
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Originally Posted by neonninja
Hi all, since I bought my LS the front stage has not worked. I have the Pioneer HU. All rear speakers work fine inc the Sub. Fader is working as I can Fade to front and get no sound at all, then fade to back and it works.

Is this a common problem? If so, where do I start looking for the issue. I really want to retain the factory audio setup.

Thanks.
Damn, I have the same exact issue- except its the balance from left to right. I am missing the left audio but I have the controls like you say you do still functioning in the amplifier. Would like to know the answer to this as well.
Old 01-06-21, 06:10 AM
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nvturbo
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Check the wiring at the back of headunit. It's either bad wiring or the stock amplifier is shot.
Old 01-06-21, 08:00 AM
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400fanboy
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Originally Posted by neonninja
Yep the whole front stage isn't working. Previous owner bought it like this so couldn't provide any more detail.


Would it be possible its the Caps in the Amp? Would all 4 channels (2 woofers and 2 tweeters) be caused by a bad Cap?
If the whole front is out, then it's probably not the speakers. Interesting how it's all located upfront though. Hopefully someone who's more of an expert in these things can weigh in, but that does sound like head unit\amp problems and probably isn't wiring. Best of luck.
Old 01-07-21, 03:29 AM
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Yamae
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The head unit only sends the front right and left signals to the amplifier unit. The unit makes the rear right and left as well as the sub woofer signals using the built-in DSP circuit. Your problem may be caused by something after the DSP. I'm an electronics guy and at first I'd check the power IC for front speakers using an oscilloscope.
Old 01-09-21, 12:16 PM
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DGMD
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My radio was intermittent my cutting out whole left side, then would come back. I got my 2000 pioneer stock non nak headunit pulled shipped to factoryradioservice.com in california repaired connections on back(fairly common prob apparently) and shipped back. Worth a try if you want to keep everything stock. They previously also replaced an lcd that is bugging out and added clean aux in solution. Try calling or emailing them with problem to see what they think.
Old 01-11-21, 10:36 AM
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timmy0tool
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^ i second DGMD's recommendation. likely the headunit internals are compromised since it's so old, and give the factoryradioservice.com a call!
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