The voltage should be between 0 and 12v. The center leg of the 7812 that you previously checked was the negative rail.
If you have a difference of 106v between legs 2 and 3, you have a problem somewhere. Are you sure that you had 106v between pin 3 of that regulator and pin 1 of U6?
If i use the Middle leg Of the 7812 and red probe on PIN 1 of U6 i get 0.06
If i use 3rd leg of the 7812 i get 11.95 volts
If i use 3rd leg of the 7812 i get 11.95 volts
That should be -12. Confirm. It's not really important but you need to be careful to include polarity.
Yes it has 2 D1302's in the amp Both have been replaced with brand new ones
Do you want me to post the voltages on them ??
Do you want me to post the voltages on them ??
It has 2 D1302 mutin transistors in it both were replaced with brand new ones...
The voltages on them are
Leg 1:-124.2
Leg 2:-122.4
Leg 3:-123.1
Its not wise to pull them out and then see if the amp has output is it ?
The voltages on them are
Leg 1:-124.2
Leg 2:-122.4
Leg 3:-123.1
Its not wise to pull them out and then see if the amp has output is it ?
I wouldn't power up the amp with them out.
Post the voltage again but with the black probe on leg 1 of the 1302.
Post the voltage again but with the black probe on leg 1 of the 1302.
They are being driven on by something. If there is no DC offset on the output filter inductors, post the DC voltage on Q4 and Q5 on the driver board. For each transistor, place the black probe on the emitter of the transistor. Remember to note polarity of the reading.
On the output filter inductors i get 1.36 volts
Q4
Base:-15.12
Collector:0.00
Q5
Base:137.5
Collector:0.00
Q4
Base:-15.12
Collector:0.00
Q5
Base:137.5
Collector:0.00
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For these, did you have the black probe on the emitter of the transistor that you were measuring the voltage on?
I will get back to you on this amp right now i seen some bad solder joints for someone else's attempted repair and im re-doing that circuit right now once i put the part back in i will post my findings
If this is the right PIn config then heres what i get on the legs of the transistors..
http://www.fairchildsemi.com/ds/MM/MMBTA42.pdf
http://www.mouser.com/ds/1/389/CD00002981-48609.pdf
Q4
Base:0.00
Collector:-15.12
Q5
Base:138.2
Collector:0.00
http://www.fairchildsemi.com/ds/MM/MMBTA42.pdf
http://www.mouser.com/ds/1/389/CD00002981-48609.pdf
Q4
Base:0.00
Collector:-15.12
Q5
Base:138.2
Collector:0.00
See post above..
Also Is this noraml of not
All of the op-amps TL072CN have the same voltages on all of them
If i use amps ground terminal as reference heres what i get
Pin 1:1.39
Pin 2:1.39
Pin 3:1.39
Pin 4:-13.33
Pin 5:1.39
Pin 6:1.39
Pin 7:1.39
Pin 8:16.89
Also Is this noraml of not
All of the op-amps TL072CN have the same voltages on all of them
If i use amps ground terminal as reference heres what i get
Pin 1:1.39
Pin 2:1.39
Pin 3:1.39
Pin 4:-13.33
Pin 5:1.39
Pin 6:1.39
Pin 7:1.39
Pin 8:16.89
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