How to Fix 2 Blinks Error on Sony LED TV KLV-48W652D step-by-step
Overview
Recently, I received a Sony LED TV model KLV-48W652D at my workshop for repair. The issue was that as soon as the TV was plugged in, it immediately shifted to the 2 blinks error. There was no logo displayed, only a red light appeared, and then it started blinking twice repeatedly.
- Here’s the step-by-step breakdown of how I fixed the problem:
1. Initial Inspection
- I brought the TV into my workshop lab and began a detailed inspection.
- All the voltages on the main board were checked.
- The key voltages were present, which indicated that the issue might be elsewhere.
2. Voltage Reference Check
I traced the reference voltage, which should be around 2.1V.
This reference voltage is important because it senses the 19V power supply and signals the system IC that the supply is available.
The reference voltage is generated by a voltage divider made up of two resistors:
One resistor connects to 19V,
The other connects to ground,
The center tap of this divider feeds the signal to the system IC.
Exact fault point located
- After searching, I found the faulty voltage divider resistors.
- The faulty resistor was R1, the one that provides positive voltage. It had a value of 82k ohms.
- Replacing R1 with a new resistor solved the issue.
Question: Why does the 2 blinking error occur in Sony TVs?
Answer:
In some Sony TV models, an external 19-volt power supply is used. This power supply is crucial as it is sensed by the system IC to verify that the 19 volts are present and functioning correctly. These models have a specific voltage divider resistor in the circuit that reduces the 19 volts to provide a 2.1-volt reference to the system IC.
If the value of the resistor in the voltage divider changes, either due to an increase or decrease in resistance, the voltage provided to the system IC will fluctuate, leading to the 2 blinking error. This issue typically arises in models that use an additional power supply, where a malfunction in the voltage divider resistor can disrupt the voltage reference to the system IC.