Hello All,
I have been over and over and over this. When I made a temporary connection to the broken lead on a transistor all was well. When I decided to replace it the distributor gave me an ECG 234 as a correct sub because the leads on the 2SA750 were too short to work.
I replaced the transistor and expected that all would be well having found the problem. But all I got was a thin waft of smoke and the protection circuit absolutely refuses to allow the amplifiers to turn on. I have checked everything. There are ZERO solder shorts. There are no defective components I can find. All the electrolytic capacitors were replaced, all resistors are now of the correct value. I took the transistor out and it still wont turn on. The schematic is in the other thread where this left channel was distorting because one side of the push pull wasn't on due to this "open" transistor.
So what happened? Please help.

Thanks,

Dave

Hello again Dave. The ECG is the correct sub, however the pin base could be different. Are you sure the E-B-C leads are in correct? I know you can use ECG for output transistors in the Sansui. BUT, remember being told by Sansui, " subs are NOT recommended " I always used OEM parts from the MFG doing warranty service.
Now what smoked ? You have a short now, even with the new transistor out of the circuit. I would suspect TR-04 TR-01. hope not the audio outputs.

Warren,
There is no "short" anywhere that I can find. There's no open that I can find. Everything is as it was, but it isn't for some reason. No, the ECG transistor has exactly the same pin-out. But I will take the amplifier out and examine it yet again.

Thanks,

Dave
: Hello again Dave. The ECG is the correct sub, however the pin base could be different. Are you sure the E-B-C leads are in correct? I know you can use ECG for output transistors in the Sansui. BUT, remember being told by Sansui, " subs are NOT recommended " I always used OEM parts from the MFG doing warranty service.
: Now what smoked ? You have a short now, even with the new transistor out of the circuit. I would suspect TR-04 TR-01. hope not the audio outputs.
:

That little " waft " of smoke, there is most likely a small value resistor open now where that came from. Maybe use a magnifier glass, look over the board to find it. When you were removing that brown poop before, could be a component lead got bent over? Long shot I know, could happen. Post again if & when you find anything, if you would like the full print and service information I have it.

Warren,
I also have the service data.

Thanks,

Dave
:That little " waft " of smoke, there is most likely a small value resistor open now where that came from. Maybe use a magnifier glass, look over the board to find it. When you were removing that brown poop before, could be a component lead got bent over? Long shot I know, could happen. Post again if & when you find anything, if you would like the full print and service information I have it.
: