Hi there everyone hope you can help me i recently had a sny ta-fb740r amplifier for fixing as per usual transformer had blown open circuit on mains side ...unusual rthing is there are 5 terminals on secondary as shown in schematic ...i dont know what the voltages are i got another with three on the output jumped the 2 ac outs to the other extra 2 and the amp hums i then connected the 2 extra to earth and still hums , hope someone can help as due to transformer being blown i dont know what the voltages were , on the board the 2 trim pots make no difference except raising and lowering the dc rails , if i connect a wire form the ov out on the transformer to the heatsink humming is louder .....The humming is there regardless of volume it gets louder when turned up to maximum , present on every input with source connected or not ..Thankyou in advance ...Also changed rectifier,big psu caps and the 4 smaller ones also .
here is the picture of power supply ..
Hi there everyone hope you can help me i recently had a sny ta-fb740r amplifier for fixing as per usual transformer had blown open circuit on mains side ...unusual rthing is there are 5 terminals on secondary as shown in schematic ...i dont know what the voltages are i got another with three on the output jumped the 2 ac outs to the other extra 2 and the amp hums i then connected the 2 extra to earth and still hums , hope someone can help as due to transformer being blown i dont know what the voltages were , on the board the 2 trim pots make no difference except raising and lowering the dc rails , if i connect a wire form the ov out on the transformer to the heatsink humming is louder .....The humming is there regardless of volume it gets louder when turned up to maximum , present on every input with source connected or not ..Thankyou in advance ...Also changed rectifier,big psu caps and the 4 smaller ones also .
Hi there everyone hope you can help me i recently had a sny ta-fb740r amplifier for fixing as per usual transformer had blown open circuit on mains side ...unusual rthing is there are 5 terminals on secondary as shown in schematic ...i dont know what the voltages are i got another with three on the output jumped the 2 ac outs to the other extra 2 and the amp hums i then connected the 2 extra to earth and still hums , hope someone can help as due to transformer being blown i dont know what the voltages were , on the board the 2 trim pots make no difference except raising and lowering the dc rails , if i connect a wire form the ov out on the transformer to the heatsink humming is louder .....The humming is there regardless of volume it gets louder when turned up to maximum , present on every input with source connected or not ..Thankyou in advance ...Also changed rectifier,big psu caps and the 4 smaller ones also .
- Status
- Not open for further replies.