[0-30V Stabilized Power Supply]

Audioguru,

I have replaced the power transistor (Q4), R7, Q1 and tested with a (just purchased) multimeter to see whether any of the capacitors are non operational but still no output from the power supply. I don't think any of these were blown but they seemed to be likely candidates, so replaced them.  Not sure what to do next.

Would the op amps be the problem? If so how can these be tested? Replacing them?

Thanks,

Philip

[0-30V Stabilized Power Supply]

Sorry - so far as I can see, my device uses the current circuit.

I have built a few electronic devices but all of them have worked fine.  I would know how to test resistors, the transformer (which is working fine) and rectifiers but not sure how to test transistors.  How can I do that?

Philip

[0-30V Stabilized Power Supply]

I built this power supply a couple of years ago and have used it for a variety of tasks.  Tonight I was using it to try to run a 12v motor (around .5A) but the motor seems to have a problem (perhaps shorted) and now my power supply isn't supplying any power.  There is power to the board from the transformer.

What would be the most likely component to have blown?

Should I have added a fuse somewhere?

Philip