You can read the zener diode numbers and look up what their voltage should be. Better yet, I would suggest getting your amp to an ARC warranty repair place before you possibly rip the through hole plated traces up and then it's not worth repairing.
regulator in AR D70
Hallo ! The screens are fed from a single 6550 tube , about
335 VDC . Also a TIP 41 powertransistor gets this voltage to its collector and in turn feed the 6FQ7 tubes with 327 VDC.
A Darlington trans. , D40k1 is connected to the base of TIP41
and finally an OP , TL071 feeds this Darlingtontr. My PROBLEM is that these transistors seem to be fully open and I get almost 335 VDC out from the "TIP". Which component can I suspect to be wrong ? Which voltages except those I mention are critical ? R80 , 27K , passas almost 12mA . Shall the voltage over this resistor be about 311 VDC ? Well , thanks for some help . The TIP 41 is checked outside the unit and it was OK .... Stewen
335 VDC . Also a TIP 41 powertransistor gets this voltage to its collector and in turn feed the 6FQ7 tubes with 327 VDC.
A Darlington trans. , D40k1 is connected to the base of TIP41
and finally an OP , TL071 feeds this Darlingtontr. My PROBLEM is that these transistors seem to be fully open and I get almost 335 VDC out from the "TIP". Which component can I suspect to be wrong ? Which voltages except those I mention are critical ? R80 , 27K , passas almost 12mA . Shall the voltage over this resistor be about 311 VDC ? Well , thanks for some help . The TIP 41 is checked outside the unit and it was OK .... Stewen
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