I measured 2.3Ω on each. I took photos but I've been hit with the amazon rewards spinning wheel virus on my iPhone. Never had this happen. Apparently it comes from ads within the AK site. Do you need to see the photos?
Should be reading higher than that Pete, should be about 5Ωtouch your meters probes together and deduct what you see as the readings .
Photos of the measurement from one transistor to the other on right channel.
i am looking at it a different way yet again .. please carry on .. sorry for the interruption .. best me not bring more variables in to playShould be reading higher than that Pete, should be about 5Ω
was trying to figure the good parts from the misreading ..i am looking at it a different way yet again .. please carry on .. sorry for the interruption .. best me not bring more variables in to play
I'll run out and check it again. While I am doing that, attached is the same photo with some added text.In your first picture, it looks like you are on the centre Pin of that driver, you should be on the right hand pin of the driver...
Okay, thats not right, so now we have to start eliminating.
You have to now find the BASE resistors for the output transistors, they are on the F2980 board near the emitter resistors, they will be those bluish ones with the S bends on the legs. They are 1/2 Watt. The manual states 4.7Ω, but who knows with these Sansui's, they may have changed them. Locate those and measure them, I do not think the schematic is correct for the identification numbers.
You an measure from the end closest the output transistors, to the BASE of the corresponding output transistor, you should get something like 0.2-0.4Ω, in other-words, a direct connection.
then from the other end of the resistor back to the EMITTER of the driver transistor.
So we need three readings. Surrounding the BASE resistors.
1, the resistor Ω
2, Resistor to Output BASE.
3, Resistor to Driver EMITTER.
He has 100Ω emitter resistors in there at the moment. That is why the voltage is that high.sorry for butting in again ..what are voltages across r72 r78 . two readings ..
ah ..i missed that bit .. even so knowing each voltage to see if a relative match isnt a bad idea to see ,.Never start with the Bias trimmer in the middle.
Only start the DC offset with the trimmer in the middle.
He has 100Ω emitter resistors in there at the moment. That is why the voltage is that high.