The Konka T2988P TV has no response when turned on, and the indicator light does not light up.
Analysis and Maintenance: The voltage at the top end of C809 is measured to be 300V, and the voltage at the top end of C831 is 12V, estimating that the fault lies in the voltage regulation control loop. The voltage at the b terminal of V823 is measured to be 0.14V (normally 0.4V), and the voltages at the c, b, and e terminals of V824 are 0.3V, 0.3V, and 0.9V respectively, which should normally be -40V, -14.0V, and -14.3V. Upon checking the peripheral components of V824, it was found that C833 had broken down and short-circuited.
Maintenance Tip: This fault is caused by the breakdown of C833, causing a significant increase in the current of R827, reducing the internal resistance of V833, increasing the shunting effect of the current at the b terminal of the switching transistor V823, shortening the saturation conduction time of V823, and causing an abnormal drop in the voltage of C831.
Handling Method: After replacing C833, the fault was eliminated.
Technical data for Beijing Konka TV repair hotline.