Show up and down keys can't choose of the remote control and keyboard (press show up and down automatically jump to 0), manual and automatic tuning can lock can (scan), signal snowflakes big at the same time. cawservice manual download site
Scanning lock and AFC voltage of the output pulse line, line synchronous identification signal. So should be related to the signal. cawservice manual download site
Check: cawservice manual download site
1) each foot IC1213 voltage as table "MN1872432TW1 (voltage). From the analysis of 39 feet H line SYNC output pulse signal, 7 feet STOP (STOP + h. series) identify the basic normal line synchronization. AFC voltage of 2.09 V and 10 feet drawings below the reference voltage of 2.5 V. cawservice manual download site
 cawservice manual download site
 cawservice manual download site
2) found that AFC OUT of 12 feet signal is low, and a far cry from what AFC VCC of 18 feet. 18 feet from circuit analysis is directly connected to the 12 v power supply side, without any element. cawservice manual download site
Check the high-frequency head and B2 5 side, 12 v voltage is normal. Check the IC foot welding, good estimation is circuit board wiring problem. Carefully check both sides found is double-sided circuit board has a hole corrosion because of covering open, causing an AFC VCC side may not 12 v voltage. cawservice manual download site
Treatment: cleaning circuit board, jumper 12 v to 18 feet. Circuit is back to normal. AFC VCC measurement of 18 feet is equal to 5.63 V. cawservice manual download site
Note that after recovery, snowflakes all eliminate TV signal. Can also be adjustable table lock. But according to the up and down keys or automatically jump to show 0, but then can back to the original machine at a time. Start also suspect the CPU has a problem, but when you perform a full automatic scan tone, press show up and down back to normal. Seems to show up and down keys of normal function must be performed in a fully automatic scan adjustable back to have.cawservice manual download site