**Solution:** Replace Q802, and the fault is eliminated.
**Analysis and Maintenance:** The microprocessor QA01 (CXP80424-165S) of this machine has a character display function, but it must meet the following three conditions:
(1) Pin 47 of QA01 must have a field blanking signal input.
(2) Pin 48 of QA01 must have a line blanking signal input.
(3) The external character display oscillator LAOI connected to pins 45 and 46 of QA01 must oscillate.
Based on the above analysis, measurements show that pin 47 has a reverse pulse input for the line, while the voltage at pin 48 is 0.9V (it should normally be 4.6V). Upon inspection, it was found that the external component Q802 (2SC1815) has been breakdown between its collector and emitter.
**Technical Information for Beijing Toshiba TV Repair Hotline**
Toshiba 3429KTP type TV, Beijing Toshiba TV repair, no character display on the screen.