A day establishs phenomenon of breakdown of CM2988 color television to resemble to have breathed, AV input is normal, open machine lid to switch on the mobile phone to feel box of decipher of its Li Yin to warm a hand in a few minutes, the access of TV audio processing of this machine is: Audio signal the 1st foot from IC801 is derivative, 12 what send Li Yin the case, 13 feet, again of Cong Liyin box 15 with 16 feet output comes 22 of IC1301, 25 feet, IC1301 is by IC of switch of CPU pilot AV. Catch us audio line (the 1st foot that puts 1C801 from which) the capacitance bond that uses a 10UF arrives of Li Yin box 15 with 16 feet, audio appears, consider price of beautiful sound decoder is high bad still to search and this function is temporarily trashy, li Yin for this cut piles up box discharge to drop, 12 of beautiful sound box, 13 feet jump directly receive 15 with 16 feet, try machine discovery to want to wait for 15 seconds to control audio to just appear normally, and when changing a table every time such, to this we undertake an analysis to circuit afresh, decoder of this beautiful sound is by pilot of IC bus line, so the character of IC bus line is in the basis to switch on the mobile phone every time or the CPU when changeover channel wants to receive the IC on bus line to undertake detecting to hanging, if discover in detect some IC did not respond to signal, CPU can undertake detecting to this IC repeatedly, this makes detect the time of the process increases greatly, appear so afore-mentioned phenomenon. The circuit structure of box of our anatomize Li Yin, discover the circuit inside it distributes a share, one is part of several word processing, one is part of imitate signal processing, the power supply of its number part is 5V, imitate part power supply is 9V, we try to disconnect the power supply source of its imitate part (disconnect the 11st foot of Li Yin box, the purpose is the job that quits imitate circuit part and digital part continues to work. ) beautiful sound box tries mount afresh machine, everything is normal, feel beautiful sound case also no longer soup hand, the circuit of part of imitate signal processing that this shows this beautiful sound case damaged and digital part is good, the machine after the course is handled so child return to normal use.