Afternoon all, novice here, please be gentle........ I have been trying to bring an old amplifier back to life, it initially started up but there was obviously something not right, so after doing some initial inspections, minor tidying up inside and replacing a missing resistor, I powered her up and said missing resistor turned up...... shorting the output of the switch mode power supply
![ThumbsDown :--](https://www.eevblog.com/forum/Smileys/default/icon_thumbsdown.gif)
I have pulled 80% of the components off the power supply board for testing and have yet to find anything major, I have also done a full recap of all the electrolytics. Now, I have tried powering it back up with a variac but the output from the power supply cuts out at around 30v with a little squeak from one the components. From my initial testing, input to the SMPS is fine, 240v input (AC), gives 320v (DC) in to the SMPS as per the schematic.
The only thing thus far that I have not attempted to remove and test is the transformer T603. Could anyone please take a look at the schematic and tell me whether it is likely that the transformer could have blown a winding?
Any other pointers more than welcome....
I have attached the schematic.