I measured voltage with this 3010D power supply but accidentally very high voltage happend to be on a measuring point. As a result, plus input of that power supply is shorted to ground.
Is there a schematic available ? Or anyone already solved a such problem in the past?
Thank you for help
Hello there Jane,
It is probably a simple problem but the solution probably cant be found on the schematic anyway because they probably dont show the component you need to replace. It's a simple diode like the 1N5400 series.
What they do is connect that diode directly in reverse parallel to the output terminals of the power supply so that if another power supply tries to power the unit in reverse the diode will conduct and sink the current and probably blow out in the shorted condition.
It could also blow with a higher voltage input than the diode is rated for. Again the diode would blow out in the shorted condition so it has to be replaced.
To replace it you have to remove the internal circuit board, then you can find it. It is mounted fairly close to the output terminals so look there. It is not easy to find without removing the board though you may not even be able to see it without taking out the board.
Once you spot it, it will probably be cracked which means it burnt and became a short.
It's a simple way to help protect the power supply from blowing out completely if something that provides power to the input gets accidentally connected to it. The same will happen if you connect a large 12v lead acid battery in reverse to the input terminal polarities.
I hate to say it, but there could be other things wrong too if the diode didnt catch the fault in time, but the diode is the starting point. You can test it to see if it is shorted then replace it and hope for the best.
I have a schematic for a similar power supply the HY3010E if that can help i can try to find it. It does not show the protection diode either but the connection is very simple as explained above.
Good luck with it Jane, and i hope you can report back here on your progress with this power supply.