Native CPU use TMP47C433AN, or LK5103. In the search process, if there is no TV signal, grating static noise, only the characters in the output. Characters and the noise when no signal appears, the problem is:

(1) poor CPU D001 in the search when there is no signal, grating static noise no output terminals 11 feet high.
At 11 the output high, which saturated V007 and V006 V006 set 12V. By V032, V031 the close pass by and brightness from the grating static noise.
Measure the voltage to distinguish fault R031 range. Search without signal R031 voltage between 5V and 0.6V, respectively. If there is no voltage 5V, issues D001 if 5V voltage, problems in V007 and V006 R031 measured voltage and related components in the search status at one end for 5 v and the other end to 0V R031 further measurement, check V007 b-e breakdown. Troubleshooting after replacing V0.