incorrect wiring or assembly.
has the bulb lit up to indicate excessive current draw?
Yes they are, in fact I should mention that I've two PSU boards, while they are from different revision, they are quite similar, and one is working and the other one with the same toroid doesn't.
https://goo.gl/photos/SbMx6qJSAxFM24rv6
please:
I'm a newbie and was not soldered or assembled by me ;-)
https://goo.gl/photos/TXdvWRW73HMS3Bcq8
I'm a newbie and was not soldered or assembled by me ;-)
https://goo.gl/photos/TXdvWRW73HMS3Bcq8
I hope your friend who assembled them is a butcher by trade...
The underside of the board looks awful. One capacitor leg looks like it has a big old void in the solder and you might have a solder bridge on the edge connector (top right in the last image).
If I was you I would safely discharge the caps (Andrew will tell you the safest way) then I'd resolder all the joints making sure there's no 'strands' of solder running to the gnd plane where there shouldn't be.
I'd also replace that damaged cap.
Do you have a decent soldering iron? 30 watt plus with a big heavy tip?
The underside of the board looks awful. One capacitor leg looks like it has a big old void in the solder and you might have a solder bridge on the edge connector (top right in the last image).
If I was you I would safely discharge the caps (Andrew will tell you the safest way) then I'd resolder all the joints making sure there's no 'strands' of solder running to the gnd plane where there shouldn't be.
I'd also replace that damaged cap.
Do you have a decent soldering iron? 30 watt plus with a big heavy tip?
Thanks for advice, I will speak with him and see how to fix that.
It would also be interesting to butcher it a little bit more ;-)
Yes I can solder (you know, crossover, rca's...Andrew will appreciate;-)
As has already been said, run around with the soldering iron again to clean up all the joints and then clean off the flux residue which will allow you to inspect the joints better
Given the simplicity of the circuit there really is not much that can be wrong.
You say the unconnected transformer secondaries are good. What are they like when connected to the board? With no PSU load they should be about the same.
The caps look the right way around.
The only thing I can think of is a damaged rectifier as you are seeing about 1/2 voltage.
Given the simplicity of the circuit there really is not much that can be wrong.
You say the unconnected transformer secondaries are good. What are they like when connected to the board? With no PSU load they should be about the same.
The caps look the right way around.
The only thing I can think of is a damaged rectifier as you are seeing about 1/2 voltage.
As stated the circuit is very simple and the main components in the path are the bridge rectifier and the capacitors. Other than that it has to be wiring or a short.
Do you have a multi-meter that can read AC current? If so you could wire it in series with the transformer feeds and see what the current is. With no load it should be negligible after the caps have charged. If there is an large imbalance then it confirms a short or defective component (cap or rectifier). If they are both minimal then I'd say the rectifier or a dry joint.
Also you could swap the caps over to see if the fault moves.
Do you have a multi-meter that can read AC current? If so you could wire it in series with the transformer feeds and see what the current is. With no load it should be negligible after the caps have charged. If there is an large imbalance then it confirms a short or defective component (cap or rectifier). If they are both minimal then I'd say the rectifier or a dry joint.
Also you could swap the caps over to see if the fault moves.