Car Amplifier have power but no sound. Please help me

[Perry Babin]

Did you install 18v Zeners instead of 15v?

When installed, did the two zeners read their rated voltage when measuring the voltage directly across them?

Does the Zener now read shorted?

What was the part number of the Zener you installed?

 

[Hackersingh]

Did you install 18v Zeners instead of 15v?

No, it was 15v Zeners.

 

[Hackersingh]

When installed, did the two zeners read their rated voltage when measuring the voltage directly across them?

yes but those voltage was 18V.

 

[Perry Babin]

Does the Zener now read shorted?

Are you saying that, after the 15v Zener was installed, you read 18v across it?

Is the jumper shorting to pin 1 of the op-amp?

 

[Hackersingh]

Does the Zener now read shorted?

Yes.

 

[Hackersingh]

Are you saying that, after the 15v Zener was installed, you read 18v across it?

Yes.

 

[Hackersingh]

Is the jumper shorting to pin 1 of the op-amp?

I think jumper is fine and not interfering with any ICs because it was worked perfectly when my amp was not shorted.

 

[Perry Babin]

You 'think' the jumper is fine?

^^ Why not confirm?

Remove the op-amp that was heating up.

Remove the shorted Zener but don't power up the amp without it.

You stated that both large resistors were 150 ohms. Do you read 150 ohms across each one while in the board?

Has the rail voltage changed from ±18v?

What was the 12v supply voltage when you read ±18v of rail voltage?

Please answer all questions.

 

[Hackersingh]

Remove the op-amp that was heating up.

i already remove it. Please tell if op-amp's vcc+ and vcc- give beep in continuity mode then what its mean.

 

[Hackersingh]

Bro, I found the same video on YouTube which happened to me but it is in Hindi but you can use subtitles.

 

[Perry Babin]

I don't watch repair videos. If it's the same, did it solve your problem?

If not, please answer the questions I posted.

 

[Hackersingh]

If not, please answer the questions I posted.

Bro I have answered your question please see

 

[Perry Babin]

You stated that both large resistors were 150 ohms. Do you read 150 ohms across each one while in the board?

Has the rail voltage changed from ±18v?

What was the 12v supply voltage when you read ±18v of rail voltage?

If it's the same, did it solve your problem?

 

[Hackersingh]

Thank you brother. My amp is working now and the problem was in the two TL074CN op-amp ICs.
I can't find these op-amps near me but I will replace them soon but after removing them temporarily the rest of the channels are working now.
This wouldn't have been possible without your help, you taught me a lot about amps. Thank you.

 

[Hackersingh]

Hlo,
I replaced the old OP-AMPS but now the Channels Transistors of left side getting hot when speaker is connected.

 

[Perry Babin]

If you measure directly across the two speaker terminals of each channel, what is the greatest DC voltage you read on any channel?

 

[Hackersingh]

If you measure directly across the two speaker terminals of each channel, what is the greatest DC voltage you read on any channel?

In the left channel which is not working it shows 0.70 V and in the right channel which is working it shows 0 V.

 

[Perry Babin]

Have you removed 100% of the brown fixative that's been applied to some of the various components?

What's the DC voltage on all of the output terminals of the op-amps you replaced?

 

[Hackersingh]

Have you removed 100% of the brown fixative that's been applied to some of the various components?

Yes.

What's the DC voltage on all of the output terminals of the op-amps you replaced?

30V In the right side and 0.25V in the Middle one and 0.25V in the left side's small op-amp.

 

[Perry Babin]

There are 4 output pins per each 14 pin op-amp. You need to post the pin number and the voltage.

Is that an old photo? I see the fixative on some components.