eric_wang

Hi, if you want to ask a question, you can click the "Edit" button to re-edit or post a comment to explain the question.

eric_wang

Xinfadi published on 2019-11-12 15:36 Unable to upload, what's wrong with the picture

There is no problem in testing uploading pictures. If the picture is too large, you need to wait for a while depending on the network environment.

qwqwqw2088

It should be the no-load measurement.

The image shows the power supply under repair

What kind of power supply structure is it?

Transformer leakage inductance and feedback part may affect,,,

maychang

Judging from the photos, the power is not large, and it is powered by AC mains. I guess it is a single-ended flyback circuit.

If the single-ended flyback circuit is not designed well enough, the voltage will rise higher when the output is unloaded, and a suitable load should be added for measurement.

乐在其中1100

Come in to study.

maychang

Xinfadi published on 2019-11-13 09:27 The voltage of the diode for measuring electricity is also 17V, and the diode model is 18v

"The voltage of the measuring diode is also 17V, and the diode model is 18V"

I don't know what instrument you use to measure the "diode voltage". It would be best to post the electrical schematic and indicate which point the voltage is measured.

qwqwqw2088

Xinfadi published on 2019-11-13 09:26 The monitor switch power supply 24V, 5V, are normal, only 12V is abnormal

24V, 5V, both are normal, only 12V is abnormal

Repair the power supply, not the principle problem

Measure and view the device for replacement

maychang

Xinfadi published on 2019-11-13 09:47 After the secondary of the transformer comes out, it is rectified by a diode. The voltage of the diode is 17v, which should be 12v

"After the transformer secondary is rectified by a diode, the diode voltage is measured to be 17v."

My question to you is: what instrument do you use to measure the "diode voltage".