how to repair sony led tv volume increased
I recently had the opportunity to repair a Sony LED TV klv-40r330c that was experiencing a sound issue. The problem was that the volume automatically increased without any user input. Upon opening the back cover, I discovered that the keyboard switches, which control the TV’s functions, were installed on the main board in a corner of the set.
Fault Diagnosis:
To start the troubleshooting process, I checked the voltage on the key1 and key2 tracks connected to the keyboard switches. I noticed an unusual increase in the voltage on these tracks, which indicated that something was wrong. After a closer inspection, I focused on the resistors associated with the keyboard switches. Specifically, I found that one of the 10K resistors, which were supposed to regulate the key input, was showing a much higher resistance value than it should have.
Fault Finding:
The higher-than-normal resistance indicated a fault in the resistor. To confirm, I replaced the faulty 10K resistor with a new one, and this resolved the issue. The volume no longer automatically increased, and the TV functioned as expected.
Highlighted Fault Area
Highlighted Fault Area
The fault area has been clearly marked in the provided photo for your convenience. Kindly examine the image to identify the specific section where the problem exists.
Conclusion:
In this particular model of Sony LED TV, the keyboard switches were installed in a corner of the main board, and the faulty resistor was located near the switches. The replacement of the faulty resistor fixed the sound issue. The image below shows the faulty resistor and switch, providing a clearer view of the repair work done.
sony-klv-40W652D-sound-is-muted