In the machine is energized sub were measured the terminal voltage of power supply to the motherboard socket CZ10, found that in addition to the CPU + 5V normal to decoding which is the part of the 5V 0V, to the motherboard +, + 12V to 0V. When the power button is pressed, the ON POWER is always 0V, and it should be 5V. Because the decoding part of the 5V and 8V, 12V voltage are controlled by CPU, when the CPU POWER (ON), the power supply part to output +5V, +8V and +12V voltage. When the power button is pressed, the ON POWER level is always 0V no change, so it is concluded that part of the CPU is faulty, and the starting instruction is not issued. Xinke 320 VCD machine adopts CPU models CXP82220 - 143Q. Its normal working conditions for: 1, 89, 90 feet have a 5V supply voltage; 2, 38 feet 5V voltage reduction; 3, 39, 40 foot external 10MHz clock signal is normal; 4, external key control circuit without short circuit or leakage. Check 89, 90 foot on the 4.9V voltage (830B meter), the 38 foot 4.97V. 10MHz clock signal with oscilloscope normal. Doubt panel key control circuit is a problem. One by one according to seize the key on the panel are examined and found in the press to "audio mode" button, no party "tick tock" sound, with R x 1 retaining measure the button of the two pin between Yin value is only 0.4 ohm that the key may short-circuit or stuck and need to remove the panel control circuit overhaul. Because cannot press the key boxes so that the tray out tray does not protrude out of the will not be able to remove the panel, and special structure of St movement to hand out of the box. The author uses to the tray motor plus 4.5V DC voltage method successfully withdrew from the tray, the method is as follows: pull on the left side of the motherboard of ce03 plug, in its out2, out1 foot access 4.5V dry battery or DC power supply. If the tray is not out, the power of positive and negative change, you can smoothly exit tray. Remove the front panel control circuit are examined. It is found that the Au - DIO mode button (i.e. s525 micro button) has been severely corroded, due to the different specifications of the touch key substitution, hence from the machine is not commonly used three lifting regulation button in the demolition of a loaded in the s525 position. At the end of recovery and related circuit cable installation, power test machine, to boot. In the disc, has been able to play smoothly, and other functions were normal.

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