Changhong plasma TV 3D42A3700iD soundless map failure repair - android - Phones Developers

Filter 18.432M

Brand AVX TPSE226M035R0125 Low impedance tantalum capacitor AVX 22

I have sent a help post, see for details: "[Help] Changhong Changhong 3D42A3700iD plasma TV has no image."
The data of the plasma is too little. If there is no substantial progress in the query for a long time, I will calm down and explore it step by step. Since the VS-ON signal is not normal, and this signal is provided by the logic board, there are two cases. :
1. VS power supply has short circuit and overcurrent phenomenon, which causes the protection action VS-ON signal to be abnormal;
2. The logic board itself has a problem;
In the first easy and then difficult, first measure the load of VS power supply, there is no short circuit phenomenon; the problem should be on the logic board, scouring the logic board, after the installation is still faulty; do not give up, no circuit diagram, then Run the circuit board, follow the VS voltage, first run to the X board, only a few filter capacitors on the X board, and then continue to run to the Y board, remove the Y board, measure the power tube, the problem comes In the D, S pole resistance of a power tube is not normal, the forward and reverse are more than one hundred Ω, which does not meet the characteristics of breakdown, find this printed trace, find two peak absorption capacitors, the appearance looks nothing But look carefully at the surface of the board. There is a sign of metal splashing underneath a capacitor. Detach the capacitor decisively. Sure enough, there is a crack between the two legs of the capacitor. The measurement has broken down. Look at the capacity of 331/1KV, at hand. There is no suitable capacity on the top, but there is 221/2KV on hand, so I took 3 221 and replaced the original 2 331. Although the capacity is the same, the frequency characteristics and the withstand voltage are better than the original.
After the replacement, simply check other power tubes without any problems. The VS voltage and VS-ON signal are closely monitored on the machine. Finally, neither the voltage nor the signal will flash again. The long-lost picture finally appears;



After starting the test for half an hour, the temperature of each road rises normally, and the capacitor replaced is only slightly hot. Since then, the maintenance is over;
Testimonial: After repairing the home appliances for so many years, I feel the "first time" excitement again; although it is very common for the regular plasma peers, it is a big step for me, and I feel that I am too lacking in this aspect. More charged.