Solution: After replacing C414 and C430 with the same specifications, the fault was eliminated.
TCL TV, after watching for half an hour, the picture line amplitude shrinks.
Analysis and Maintenance: Try to adjust the枕correction adjustment potentiometer, the phenomenon remains unchanged. Measure the line frequency pulse voltage between pins 1 and 2 of the line output transformer T402, which is too high, and it should normally be 900Vpp. Check that the external decoupling capacitor C417 connected to pin 2 of T402 is normal, then check the external D402, C414, and C430 connected to the c pole of the line output tube D402 (which is also connected to pin 2 of T402), and find that capacitors C414 and C430 have cracked.
Article Source: Beijing TCL TV Repair Phone http://blog.sina.com.cn/tcldianshi.