The resistor R614 at the C pole of the overcurrent protection tube V603 for the beam current measurement has a voltage of 95.

**Model KONKA T2977B TV, the beam current overcurrent protection transistor is damaged.**

**Fault Symptoms:** For the KONKA T2977B model TV, after turning it on, there is no image, no raster, and no sound, but the power indicator light is on.

**Analysis and Repair:** Based on the fault symptoms, the voltage at the positive end of C401 was measured to be around +300V, and the positive end of the remote control power supply C447 (100uF/25V) had a voltage of about +10V. Further measurement showed that the voltages at the b and e terminals of the switching transistor V401 were both zero, while the c terminal had 300V, indicating that V401 was in a cut-off state. Upon checking, the voltage at the b terminal of V450 (V405) was 0.7V. When the R235 (15kΩ) resistor was desoldered for testing, the voltage remained unchanged, confirming that there was a fault in the protection circuit. The voltage across resistor R614 at the c terminal of the beam current overcurrent protection transistor V603 was measured, which should normally be 0V. After shutting down the TV, it was found that V603 was damaged.

**Handling Method:** After replacing V603, the fault was resolved.

**Source of Information:** Beijing KONKA TV Repair Center [http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3761213](http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3761213).