Amoi 8250 DVD player power supply principle and maintenance - Power Circuit - Circuit Diagram

The 05L0380R is an integrated circuit designed to enhance the performance of switching power supply circuits. These circuits are known for their simplicity, wide input voltage adaptability, high efficiency, minimal electromagnetic interference, and stable output voltage. Such ICs are commonly found in popular brands like Amoi and BBK. However, detailed explanations of their working principles and maintenance methods are scarce. During a repair session on an Amoi 8250 DVD player, I personally mapped out its power supply circuit, as depicted in Figure 1. Drawing from this experience and consulting relevant resources, I’ve compiled this article for fellow technicians. When testing optocouplers, it’s advisable to use the R × 10k setting and, if possible, employ the substitution method to save time and effort. Example 2: During playback, the image appears normal but there is no sound on any channel. Analysis and Repair: Given the symptoms, potential fault areas include the audio digital-to-analog converter, the analog amplifier, or the power supply circuit. Starting with the simpler checks, I measured the voltages at the F2 +12V and -12V terminals. I discovered that the -12V output was only -3.6V. Although the input voltage to the uP06 (7912) was normal, this indicated that the UP06 was faulty. Replacing the UP06 resolved the issue. Example 3: The device fails to boot at all. Analysis and Repair: This machine had been struck by lightning. Upon opening the case, I observed that the AC fuse FP01 (1.6A250V) was blown and discolored, suggesting a severe short circuit. Further inspection with a multimeter revealed that the UP012 pin was shorted to ground, along with pins 3 and 4 of UP02 being damaged. After replacing these components and powering up, the output voltages were normal when disconnected. Once the motherboard was reconnected, the device functioned correctly. Testing different types of optocouplers requires using the R × 10k setting. Whenever possible, substitution is recommended to avoid unnecessary complications. When repairing various electronic devices, having a thorough understanding of their internal workings can significantly expedite the troubleshooting process. For instance, knowing how power supply circuits interact with other components can help isolate problems quickly. Additionally, maintaining accurate documentation of repairs can be invaluable for future reference and learning. In conclusion, mastering the intricacies of power supply circuits, particularly those involving ICs like the 05L0380R, is essential for efficient troubleshooting and repair. By leveraging practical experience and theoretical knowledge, technicians can address a wide range of issues effectively.

Solar Panel

Solar Panel,,High Efficiency Mono Solar Panels,Bifacial Jinko Solar Panels

PLIER(Suzhou) Photovoltaic Technology Co., Ltd. , https://www.pliersolar.com