DK112 flyback power supply universal repair board

When the switching power supply has no output, as long as the primary and secondary rectification and filtering are intact, the transformer and RCD circuit are intact, this module can be connected to the switching power supply without output and replace the original control chip circuit to quickly find the fault point. Carry out repairs or temporarily replace it for emergency use.

1. Only suitable for repair and replacement of flyback switching power supply circuit, the original control chip must be removed.

2. It must be confirmed that the primary rectifier and filter circuit is working properly without short circuit, and the large capacitor outputs 310V.

3. Make sure that the switching transformer and RCD absorption circuit are intact.

4. It must be confirmed that the secondary rectifier and filter circuit is intact, the diode has no breakdown, and the capacitor is not short-circuited.

5. Adjust the output voltage through the combination of three voltage regulator tubes, and try not to change the original output voltage.

6. Since the power supply circuit and switch tube are integrated in the dk112 chip, the output power is limited. It is only used for low-power temporary emergency replacement of the original circuit. Try not to use it for a long time.

As shown in the attached picture, it is a mobile phone charger with primary side feedback. The control chip, peripheral circuit and feedback circuit have been removed, and the module is connected with four wires. After powering on, it works normally and outputs 5V 200mA without pressure.

It was also tested on a 3842 flyback power supply and it works normally.