Test manager Q402 c, b and e are breakdown, other did not see abnormalities. After 2 sdl887 manager in the same model, measuring pipe c + 130 v voltage for normal, but still 3 without. When the machine is normal, after turning on the power supply power supply instructions for the green, a shiny red then, blinking back out ten times, built-in RL801 relay, absorption of frames before the image. Because there was no any information about this machine, at that time could not judge the fault. b5Nservice manual download site
 b5Nservice manual download site
After observation, part of the output voltage of switch power supply are clearly marked on the printing plate, it provides a convenient maintenance. On its measurement + 33 V, 130 V, 30 V + +, + + 8.5 V and 13.5 V, + 12 V output voltage, such as all normal, various load short circuit fault. b5Nservice manual download site
 b5Nservice manual download site
To analyze the cause of pipe breakdown and the resulting damage, draw the machine line circuit diagram of a part, as shown in figure 1. Test manager Q402 b without excitation voltage, further inspection, found that the machine line driver circuit different, it is composed of nine feet single-row TDA8143 integrated blocks, the circuit is simplified, no line driver tube and excitation transformer and other components. As there is no data available TDA8143, so the analysis from the circuit shown in figure 1: pipe Q402 three pole are breakdown, + 130 v voltage by Q402 b R401 Ω (27) directly into TDA8143 (2) feet (output), and the working voltage of the IC is only 13 v, + 130 v voltage is cannot afford it. + 130 v direct access to TDA8143 (2 feet, which leads to the damage of the internal circuit. Electronic market and newspapers and mail order no this integration block, all kinds of IC daqo books nor is introduced, then turn to samsung after-sales service centers in Beijing, for a change, audio and video are back to normal.b5Nservice manual download site