I am working with a Sound Stream 5 channel (Ref5.1000)m for 2 days now.It is a class AB amp. It is on protect mode, I had replaced a shorted transistor (TIP41C), a burned capacitor (10uf/25v) and burned resitor(1,2K) as shown in the picture wiht red circled, other than that i checked all the components but it seems all parts are good as far as I'm concern. What I found out was, there is no rail voltage because the TL494 PWM drive is not giving pulse signal to the FETs gates. The TL494 seems good I believed because I can see a saw tooth wave in the pin 5 and 5 volts reference voltage on Pin 14. Pin 12 Vcc is 12 volts to the ground. So i believed the TL494 is just shutting down the pulse signal output. As measured, I am getting unequal voltages on the non inverting and inverting inputs Pin 16 and 15(error amp) . Am I missing something? I did not try to replace the TL494 yet. Can anybody shed me some light on these amp. Is The TL494 deffective?
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The voltage on the error amps won't match unless that error amp is being used for rail regulation AND the rail voltage is at its target voltage.
Copy and paste the following list and fill in the blanks. Voltage on all pins of the 494:
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
Copy and paste the following list and fill in the blanks. Voltage on all pins of the 494:
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:
Thank you again Perry for the prompt reply, Here are the Voltages on all pins of the 494:
Pin 1: 2.5 v
Pin 2: 4.2 v
Pin 3: 4.7 v
Pin 4: 0 v
Pin 5: 1,4 v
Pin 6: 3.3 v
Pin 7: 0 v
Pin 8: 12 v
Pin 9: 0 v
Pin 10: 0 v
Pin 11: 12 v
Pin 12: 11,3 v
Pin 13: 4.9 v
Pin 14: 4.9 v
Pin 15: 4.9 v
Pin 16: 7.9 V
Power supply @ 12Vdc
Pin 1: 2.5 v
Pin 2: 4.2 v
Pin 3: 4.7 v
Pin 4: 0 v
Pin 5: 1,4 v
Pin 6: 3.3 v
Pin 7: 0 v
Pin 8: 12 v
Pin 9: 0 v
Pin 10: 0 v
Pin 11: 12 v
Pin 12: 11,3 v
Pin 13: 4.9 v
Pin 14: 4.9 v
Pin 15: 4.9 v
Pin 16: 7.9 V
Power supply @ 12Vdc
I don't know what it is.
If you connect a speaker (either protected or robust) to each channel, do you get a pop or click form one specific channel?
If you connect a speaker (either protected or robust) to each channel, do you get a pop or click form one specific channel?
Just an update, I found one leaking transistor responsible for shutdown connected on Pin 16 of TL494 Error amp. Now the amp is working perfectly.
Thank you as always for your kindly response always. My journey to amp repairs are getting more challenging but I can't imagine how i am learning much now.
Thank you as always for your kindly response always. My journey to amp repairs are getting more challenging but I can't imagine how i am learning much now.