Hi gecko,
Okay, that's about 8 mA, proving those stages are active (working). Therefore I am suspicious that VR5 (bias pot) is open. Power down and discharge the caps. Measure on ohms across R33(68 ohms) and turn the bias control VR5. The resistance reading should change to almost a short at one end. Either that, or there will be no change and then an abrupt change. There may be a feeling of roughness in the pot at that point.
-Chris
Okay, that's about 8 mA, proving those stages are active (working). Therefore I am suspicious that VR5 (bias pot) is open. Power down and discharge the caps. Measure on ohms across R33(68 ohms) and turn the bias control VR5. The resistance reading should change to almost a short at one end. Either that, or there will be no change and then an abrupt change. There may be a feeling of roughness in the pot at that point.
-Chris
okay, forget about it, I found what was the problem 
and it was all my fault, now I'm feeling like an idiot 
I have changed Q13 and Q14 for a 2SC1627 but I didn't realized that it has the legs inverted, 1-E 2-C 3-B, I just got the datasheet and noticed that
Well, now it's working perfectly, thanks for all your help, and sorry for the waste of time, I learned a lot of thinks though, like think before touch anything
and it was all my fault, now I'm feeling like an idiot I have changed Q13 and Q14 for a 2SC1627 but I didn't realized that it has the legs inverted, 1-E 2-C 3-B, I just got the datasheet and noticed that Well, now it's working perfectly, thanks for all your help, and sorry for the waste of time, I learned a lot of thinks though, like think before touch anything
Hi gecko,
No problem. You learned something, so it's all good. If it makes you feel any better, I've done the same thing. That's one reason I take digital pictures beforeI take things apart. Sometimes the silkscreening on the PCB's are wrong too. I don't trust anything these days. Did I say how much I love digital camera's?
-Chris
No problem. You learned something, so it's all good. If it makes you feel any better, I've done the same thing. That's one reason I take digital pictures beforeI take things apart. Sometimes the silkscreening on the PCB's are wrong too. I don't trust anything these days. Did I say how much I love digital camera's?
-Chris
Yeah, that's a good idea to take photos before doing anything
I still have a little problem, in one channel I have alround 256 mV in the output, and the output transistors gets a little hot in a while, in the other channel I have 50 mV, and it's working well, I'm not sure what is the correct current for this amp
I still have a little problem, in one channel I have alround 256 mV in the output, and the output transistors gets a little hot in a while, in the other channel I have 50 mV, and it's working well, I'm not sure what is the correct current for this amp
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