TCL LCD TV L37M61B boot blue light is sometimes no image repair - android - Phones Developers

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I recently worked on a TCL LCD TV model L37M61B that was experiencing an issue with the blue light being bright, and sometimes there was no image at all. The screen would occasionally spark or show a plaque, and the unit had to be restarted multiple times before it would display properly. To diagnose the problem, I used an Agilent U1252B digital multimeter. First, I checked the power supply, and everything seemed normal at first glance. However, when I measured the voltage from each regulator block on the motherboard using the Agilent 1252, I noticed that the 3.3V regulator had a high AC voltage, indicating poor filtering. This could cause instability in the system, leading to the issues described. After replacing the faulty electrolytic capacitors in the 3.3V circuit, the problem was resolved. The TV now starts up reliably, displays images without any flickering or sparking, and operates smoothly. Below are some photos from the repair process for reference: