User holding machine back to the home, can't wait to connect, then power test machine, did not expect press "power" button, the machine movement; then click. The machine is still quiet. The user had to repair. But it's all right for me. In order not to let the user down again, open the machine maintenance. With a multimeter measuring start control terminal board power supply socket J304 power. At the same time press "power" button, measured to voltage from a 1.2V drop 0.5V, indicating that the main control CPU has been sent in normal startup signal; and measured for the motherboard power socket J307 + 12V output terminal voltage is 11V around low; Shuntengmogua measured voltage stabilizing block U304 (7812) input end {1} pin voltage is about 12V should normally be about 17V, and measured filter capacitor c308 at both ends of the voltage 17.5V, normal. Suspected R308 (0.5) turns or Q303 (A1020) performance degradation. The C A1020, e, R308, B,, and E - junction were changed to the normal. Because of the alloy power is too small, normal work when the surface temperature is high, hot hot, has the power supply board used for fixing hot melt adhesive baked into molten state, so try a b772 substitution. After two or three hours of work, check the Q303 is only warm, that is no problem. The user of the machine home, after trial, malfunction has been ruled out.

Summary: why does this machine can not start in the user's home, and can work normally in my office? In fact, the reason is very simple, the higher the city of our city, the low power supply voltage. High power after Q303 C, e very resistance, arrived at about U304 {1} feet voltage up to 12V, and users at the lower voltage after Q303 to foot U304{1} only 10V, natural cannot make the normal work of the machine the. In this case the circuit can refer to "electronic newspaper" Ninth 2002 fourth version of the article.