I have a switching power supply, that isn't working anymore. I'm shure, thats the supply, because i crosschanged it between two cd player units.
Here's the schematic of it (also available in the service manual of the device):
http://audiowerk.at/djm2000_power.pdfThe problem:
The whole unit isn't working, nothing happens (no display, no leds, nothing).
I checked the power supply:
- fuse F1 is ok.
- voltage on primary energy store cap c5 is ok.
- voltage on output is around 7v dc (instead of 12V) on all outputs. It moves 1V up and down on a Fluke 87/V
- there is a very low klicking noise, around 1Hz, i think coming out of the transformer (i had no chance to localize it).
Anyone an idea to get it back working?
I have a multimeter and oscilloscope here at the bench and a camera for pics, if anyone needs more information. I haven't troubleshooted a switching supply before.