Car Amplifier have power but no sound. Please help me

[Hackersingh]

Why do you think that?

may be there size is small comparing with other.

 

[Perry Babin]

The TVS diodes should not be in there. They are for absorbing transients to protect devices in other types of circuits. 1W zeners are VERY commonly used in this type of circuit.

 

[Hackersingh]

bro i found something!
when i measure the voltage of diodes so there is 3.30V in D510 and 0.60V in D511.
and i also measure the voltage of those big resistors so there is 15V in left side Resistor and 19V in right side resistor.
And when it short circuited, spark came out from the left side.

 

[Perry Babin]

That was already shown (essentially) in the previous answers. The TVS diodes should not be in there.

 

[Hackersingh]

That was already shown (essentially) in the previous answers. The TVS diodes should not be in there.

bro i think that this is not the problem of diode.It is simply telling that the fault is in left side of the amp.

 

[Perry Babin]

Do you believe that one diode is for the left channel and the other is for the right channel?

 

[Hackersingh]

Do you believe that one diode is for the left channel and the other is for the right channel?

Maybe Yes.

 

[Perry Babin]

No. One produces the +15v for pin 4 of the op-amps and the other produces -15v for pin 11. The attached amp is similar.

 

[Perry Babin]

As a side note, if you get the amp working, you need to remove all of that brown fixative. It becomes both conductive and corrosive.

 

[Hackersingh]

15v Zener diodes. 1W preferred

bro as you said i did this but now the 3rd ic at bottom right is heating so much and smoke is also coming

 

[techtool]

Trying to fix this without a schematic and proper test equipment is quite difficult, even for an experienced professional.
And that board looks like it's been under water and is likely to have multiple problems.
At some point you need to draw the line...

 

[Perry Babin]

The op-amp could be defective.

What's the voltage across the power supply terminals?

Is it possible that it's shorted to that jumper?

 

[Hackersingh]

The op-amp could be defective.

but when old diodes were attached then this op-amp heating little bit means as usual.
And now i also check the voltage of evey op-amp and the voltage is 18-19V.

 

[Hackersingh]

What's the voltage across the power supply terminals?

12V

 

[Perry Babin]

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

 

[Hackersingh]

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

Bro, a new problem has come. The zener diode has failed.

 

[Perry Babin]

With 18v of rail voltage and a 150 ohm resistor, there is absolutely no reason for the Zener to fail.

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]

i watched the video on youtube and this same happen to that person but he use 12v zener diode and then everything works fine.
I think this ICs support only 12v

 

[Perry Babin]

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?

Look up the datasheet. The TL074 is rated for ±18v.

 

[Hackersingh]

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

their voltage was 18V but only in D510.