ok, man the schematic on cbtricks is a bit confusing, as the transistor voltage chart shows TR39 to be a CW switch, but the schematic shows it to be in the echo supply voltage circuit.
i believe your problem is D77 is leaky or otherwise bad.
this "diode" is actually a varistor, which is a diode that acts like a variable resistor.
part number is MA27T-A. not sure of a cross reference.
i believe that you can test D77 by removing it from the chassis, and testing it with an ohmmeter set to Rx1K scale.
the resistance should show almost infinite, if not "open".
if the resistance is low, replace it.
if that is not your problem, TR36, TR37, TR38, and D76 (5.1v zener) are the parts to remove and check.
i really believe that one of those parts will prove to be the culprit.
i remember fixing a galaxy 959 about a year ago and having to order a 5.1v zener and a 2SA1282 transistor from maycomm, but i cant remember what the initial problem was.
could have been this same issue, but i am very bad at taking notes during a repair.
let us know what you find,
LC
i believe your problem is D77 is leaky or otherwise bad.
this "diode" is actually a varistor, which is a diode that acts like a variable resistor.
part number is MA27T-A. not sure of a cross reference.
i believe that you can test D77 by removing it from the chassis, and testing it with an ohmmeter set to Rx1K scale.
the resistance should show almost infinite, if not "open".
if the resistance is low, replace it.
if that is not your problem, TR36, TR37, TR38, and D76 (5.1v zener) are the parts to remove and check.
i really believe that one of those parts will prove to be the culprit.
i remember fixing a galaxy 959 about a year ago and having to order a 5.1v zener and a 2SA1282 transistor from maycomm, but i cant remember what the initial problem was.
could have been this same issue, but i am very bad at taking notes during a repair.
let us know what you find,
LC