klv-40W652D dead fault
Sony model number klv-40W652D came to my workshop for repair. According to the customer, this set sometimes turns on. The set was completely off. Its pilot light was not even showing
Fault finding
I opened its back cover and started fault finding. First of all, I checked its supply input voltage. It was 19 volts. It was there. The 5-volt supply was also fine. I checked 3.3 volts. They were also fine. 1.5 volts were also fine. 1.2 volts were being generated very low
Fault 1.2 volt supply was very low
I started tracing the 1.2 volt buck converter circuit. It has a six-pin regulator IC. I checked the external parts of this IC. All the resistances were showing the correct value. I checked the capacitors. No leakage or short-circuit was found. Especially the feedback resistance was opened and checked carefully. But everything was fine. Only the IC was changed and checked. All that was left was to change the IC, then the 1.2 volt supply was completed and the set’s standby light also came on. When I turned it on with the remote, the set turned on, and my job was done.
