Thanks Perry for teaching me 
so can you confirm me please i'm right when i say that the value of the capcitors is 25.7µF and other have lower value? so the 25.7µF is deffective?
A friend tell me "because i haven't scope to do the test" to mesure the voltage across each capacitors "before, i must know the normal voltage in the part of the circuit"?? and if the voltage across the capacitor is under the normal voltage it may be possible that the capacitor is defective
Can you confirm me that Perry?
But to do this test, i must unmount the pcb board on its heatsink
so can i use a resistor of 3.8ohms 25W to reduce the current and do all my test without risk?
Thanks Perry
so can you confirm me please i'm right when i say that the value of the capcitors is 25.7µF and other have lower value? so the 25.7µF is deffective?
A friend tell me "because i haven't scope to do the test" to mesure the voltage across each capacitors "before, i must know the normal voltage in the part of the circuit"?? and if the voltage across the capacitor is under the normal voltage it may be possible that the capacitor is defective
Can you confirm me that Perry?
But to do this test, i must unmount the pcb board on its heatsink
so can i use a resistor of 3.8ohms 25W to reduce the current and do all my test without risk?
Thanks Perry
so can you confirm me please i'm right when i say that the value of the capcitors is 25.7µF and other have lower value? so the 25.7µF is deffective?
**** A multimeter doesn't provide enough information to tell you if the capacitor is defective. The ESR, dielectric absorption and leakage are also important. Most electrolytics have a wide tolerance range. ±20% is common. For a 22uF cap, the value could be between 17.6 and 26.4 and be within tolerance.
A friend tell me "because i haven't scope to do the test" to mesure the voltage across each capacitors "before, i must know the normal voltage in the part of the circuit"?? and if the voltage across the capacitor is under the normal voltage it may be possible that the capacitor is defective
Can you confirm me that Perry?
**** A leaking capacitor (leaking electrically) can drag the voltage down between two points in a circuit. It's possible that the capacitors began to leak (electrically) which caused them to pass more current than they should have which could have made them overheat and vent (blown vents on top of the cap). To determine if they were defective with a scope, you would have needed to view the signal on the output of the amp (with and without driving high power into a speaker). If the capacitor was defective, there would have been excessive high frequency ripple on the output.
But to do this test, i must unmount the pcb board on its heatsink
so can i use a resistor of 3.8ohms 25W to reduce the current and do all my test without risk?
**** There's no way to eliminate risk. You could have a bank of FETs rated to handle 500 amps of current and without a heatsink, it would be possible to destroy them even with a resistor in series with them. It takes very little power dissipation to significantly increase the temperature of the FETs to the point of failure.
**** If the amp is operating properly, I wouldn't be too concerned until the temperature reached approximately 100C.
**** A multimeter doesn't provide enough information to tell you if the capacitor is defective. The ESR, dielectric absorption and leakage are also important. Most electrolytics have a wide tolerance range. ±20% is common. For a 22uF cap, the value could be between 17.6 and 26.4 and be within tolerance.
A friend tell me "because i haven't scope to do the test" to mesure the voltage across each capacitors "before, i must know the normal voltage in the part of the circuit"?? and if the voltage across the capacitor is under the normal voltage it may be possible that the capacitor is defective
Can you confirm me that Perry?
**** A leaking capacitor (leaking electrically) can drag the voltage down between two points in a circuit. It's possible that the capacitors began to leak (electrically) which caused them to pass more current than they should have which could have made them overheat and vent (blown vents on top of the cap). To determine if they were defective with a scope, you would have needed to view the signal on the output of the amp (with and without driving high power into a speaker). If the capacitor was defective, there would have been excessive high frequency ripple on the output.
But to do this test, i must unmount the pcb board on its heatsink
so can i use a resistor of 3.8ohms 25W to reduce the current and do all my test without risk?
**** There's no way to eliminate risk. You could have a bank of FETs rated to handle 500 amps of current and without a heatsink, it would be possible to destroy them even with a resistor in series with them. It takes very little power dissipation to significantly increase the temperature of the FETs to the point of failure.
**** If the amp is operating properly, I wouldn't be too concerned until the temperature reached approximately 100C.
Hello
the sinus live seems work for a time
but now the supply do a strange noise when i power on the amp
the problem happen after 2 seconds the amp is on.
I can hear a hissing from the supply, i think it's the ci tl494C
and the sound seems grow up before the ci blow but the amp work and the fuse don't fail "i put a 10a fuse to protect it" and if i put a resistor of 3 ohms 25W in series with the B+ the amp don't power up and two leds stay power on and the supply do a strange noise
I fear that something explodes
can someone explain me that please?
Thanks
the sinus live seems work for a time
but now the supply do a strange noise when i power on the amp
the problem happen after 2 seconds the amp is on.
I can hear a hissing from the supply, i think it's the ci tl494C
and the sound seems grow up before the ci blow but the amp work and the fuse don't fail "i put a 10a fuse to protect it" and if i put a resistor of 3 ohms 25W in series with the B+ the amp don't power up and two leds stay power on and the supply do a strange noise
I fear that something explodes
can someone explain me that please?
Thanks
Hello Perry
No the protected is not illuminated.
sorry but i don't understand what you say
do you suggest that i remove the output inductor?
and for
"You may have to apply quite a bit of force"?
do you think the power supply of 13.8 v 12A isn't good to power up the amp?
sorry but my bad english is the problem
Thanks Perry
No the protected is not illuminated.
sorry but i don't understand what you say
do you suggest that i remove the output inductor?
and for
"You may have to apply quite a bit of force"?
do you think the power supply of 13.8 v 12A isn't good to power up the amp?
sorry but my bad english is the problem
Thanks Perry
Don't remove the inductor. Grab the inductor and twist it hard. These inductors tend to short where the windings overlap. Sometimes, twisting it temporarily breaks the short and allows the amp to power up normally. If that happens, the inductor will have to be rewound or replaced.
Force means physical force, not electromotive force.
Force means physical force, not electromotive force.
i remove the pcb board and remount it and the problem disappears
but before doing that
i do what you say and the noise seems little and don't grow up than before.
do you think it's the output inductor?
the pop noise come again
it's seems that the pop noise appear only for the first power on and after no problem
but before doing that
i do what you say and the noise seems little and don't grow up than before.
do you think it's the output inductor?
the pop noise come again
it's seems that the pop noise appear only for the first power on and after no problem
sh
The fact of the Atsany words or to reflect the extent my respect for this great forum and based on his or her artistic and all the brothers involved with the Forum and who have made all this has become a monument of value on the Internet between locations and because it may have contributed to their hearts, it has become a monument in the sky of the world of electronics congratulate me that I was between Here are the Giants and best wishes heartfelt to override this forum is always great because he still has all the credit and the educational practices of the world of electronics in the fact you all my thanks and appreciation from all my heart and congratulations to you and me Bhz great forum long as you safe - your brother Hisham
The fact of the Atsany words or to reflect the extent my respect for this great forum and based on his or her artistic and all the brothers involved with the Forum and who have made all this has become a monument of value on the Internet between locations and because it may have contributed to their hearts, it has become a monument in the sky of the world of electronics congratulate me that I was between Here are the Giants and best wishes heartfelt to override this forum is always great because he still has all the credit and the educational practices of the world of electronics in the fact you all my thanks and appreciation from all my heart and congratulations to you and me Bhz great forum long as you safe - your brother Hisham
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