Sony TA-FE230 Amplifier 120W

Thread Starter

spike1947

Joined Feb 4, 2016
496
Hi
I have a Sony DVP-SR760 Amplifier and when I connected it to my Turntable (with the volume on zero) then I just had to move the volume control nob slightly and the volume was just about right, I just thought it strange that I only had to move the volume such a small amount, anyway that was fine, the next time I switched the Amp on there was loud craking coming out of the speakers, that was with the volume at zero, they were very loud, I switched to Aux, then CD, then Phono, still loud cracking, then there was nothing coming out of the Amp., checked speakers and they are showing 6hms, so they seem not to of blown !
So the question is how do I test a Amps audio output ?.
Attached Service Manual.
cheers

Spike
 

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Audioguru again

Joined Oct 21, 2019
6,673
The volume control on the amplifier needs to be replaced. It should be marked "A" for audio logarithmic ratio.
The common cause is that since the lowest loudness end of the resistive track has a grounded terminal riveted or simply squeezed on, it has become loose from being used many times. But you might be lucky and see that the ground terminal has a poor solder joint.
 

Thread Starter

spike1947

Joined Feb 4, 2016
496
The volume control on the amplifier needs to be replaced. It should be marked "A" for audio logarithmic ratio.
The common cause is that since the lowest loudness end of the resistive track has a grounded terminal riveted or simply squeezed on, it has become loose from being used many times. But you might be lucky and see that the ground terminal has a poor solder joint.
Thanks for that
 

MisterBill2

Joined Jan 23, 2018
18,175
Before replacing the volume control I suggest using some control cleaner, which usually is available in spray cans. Do the cleaning with the amplifier off and disconnected from the maims power. After spraying rotate the control back and forth over the whole rotation a few times.
If control cleaner is not available try denatured alcohol, which is sometimes successful.
Control cleaner is a great diagnostic tool on many occasions. The fix may not last, but it can verify that a control or a switch is noisy.
 

Thread Starter

spike1947

Joined Feb 4, 2016
496
Before replacing the volume control I suggest using some control cleaner, which usually is available in spray cans. Do the cleaning with the amplifier off and disconnected from the maims power. After spraying rotate the control back and forth over the whole rotation a few times.
If control cleaner is not available try denatured alcohol, which is sometimes successful.
Control cleaner is a great diagnostic tool on many occasions. The fix may not last, but it can verify that a control or a switch is noisy.
Thanks for that
 

Thread Starter

spike1947

Joined Feb 4, 2016
496
The volume control on the amplifier needs to be replaced. It should be marked "A" for audio logarithmic ratio.
The common cause is that since the lowest loudness end of the resistive track has a grounded terminal riveted or simply squeezed on, it has become loose from being used many times. But you might be lucky and see that the ground terminal has a poor solder joint.
Hi again
Having a problem finding the correct "Carbon Variable Resistor" if needed , Sony Part number: ( RV202 1-241-408-11 RES, VAR, CARBON 100K/100K (VOLUME).
as per pic attached.
Spike
 

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Thread Starter

spike1947

Joined Feb 4, 2016
496
Before replacing the volume control I suggest using some control cleaner, which usually is available in spray cans. Do the cleaning with the amplifier off and disconnected from the maims power. After spraying rotate the control back and forth over the whole rotation a few times.
If control cleaner is not available try denatured alcohol, which is sometimes successful.
Control cleaner is a great diagnostic tool on many occasions. The fix may not last, but it can verify that a control or a switch is noisy.
Hi
Thanks for that, am going to do that now, will come back to you what the results will be !. cheers
 

LesJones

Joined Jan 8, 2017
4,174
Do you have the same problem with different audio sources when the turntable is NOT connected ? (Tuner, tape, aux.) Is the problem the same on both left and right channels ?

Les.
 

Thread Starter

spike1947

Joined Feb 4, 2016
496
Do you have the same problem with different audio sources when the turntable is NOT connected ? (Tuner, tape, aux.) Is the problem the same on both left and right channels ?

Les.
Hi
Thanks for your reply, have tried it using one speaker on each channel L & R it plays fine on both channels for about 1 min, then it cuts out , there is a relay on the board for the speaker output, that clicks out after about 1 minute !, whether anything is connected or not !.

cheers
 

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LesJones

Joined Jan 8, 2017
4,174
It sounds like the protection circuitry is coming into play and disconnecting the speakers. With no speakers connected measure the DC voltage on pin 12 of IC301 with respect to the negative speaker terminal from the time you switch on until after the relay clicks on. Repeat this test but monitor the voltage on pin 15 of IC301. Report the results.

Les.
 

LesJones

Joined Jan 8, 2017
4,174
I should have also asked if the relay clicking fault still occurs with BOTH speakers connected and with NO speakers connected.

Les.
 

Thread Starter

spike1947

Joined Feb 4, 2016
496
It sounds like the protection circuitry is coming into play and disconnecting the speakers. With no speakers connected measure the DC voltage on pin 12 of IC301 with respect to the negative speaker terminal from the time you switch on until after the relay clicks on. Repeat this test but monitor the voltage on pin 15 of IC301. Report the results.

Les.
Hi
Thanks for your reply, I think I have knackered it, shorted it between 2 pins or a wire joint next to it, very difficult to get a probe on the pins of 301, now the relay does not operate, looking for a fuse on the transformed side can't find one, only fuse I can see is the mains in !.

Spike
 

Thread Starter

spike1947

Joined Feb 4, 2016
496
It sounds like the protection circuitry is coming into play and disconnecting the speakers. With no speakers connected measure the DC voltage on pin 12 of IC301 with respect to the negative speaker terminal from the time you switch on until after the relay clicks on. Repeat this test but monitor the voltage on pin 15 of IC301. Report the results.

Les.
Yes, whether anything or nothing is connected it will trip out after a couple of mins .
 

LesJones

Joined Jan 8, 2017
4,174
It may have been easier to access pin 12 at R364 or R368. The pins either side of pin 12 are the main + and - 49 volt rails so there is a good chance you have destroyed IC301. Are those two voltages present at connector CN951 on the same board as IC301 ?

Les.
 

Thread Starter

spike1947

Joined Feb 4, 2016
496
It may have been easier to access pin 12 at R364 or R368. The pins either side of pin 12 are the main + and - 49 volt rails so there is a good chance you have destroyed IC301. Are those two voltages present at connector CN951 on the same board as IC301 ?

Les.
Hi
Sorry for late reply, got 2 nippers to look after !, I can't see CN951 on the main board, can see CN952 !.

Spike
 

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