分析检修:调暗电流可归零,以此现象,一般系两方面的原因:光源(负载)和电源,因它们每一变化均影响显示不稳。根据以往检修经验,发现钨灯的老化引起显示不稳比例较高。因此,我们先更换一只新灯,可故障依旧。测其灯的两端电压变化不定,且只有6点几伏(正常电压为11v左右),最高电压只能调至8v,始终变化,可以看出电源部 Analysis and maintenance: dark current can be reset to zero, this phenomenon is generally due to two reasons: the light source (load) and power supply, because they change each affect the display is not stable. According to the previous maintenance experience and found that tungsten lamp aging caused a higher proportion of instability. Therefore, we first replace a new light, the fault still. Measured at both ends of the lamp voltage changes, and only 6 points a few volts (normal voltage of about 11v), the maximum voltage can only be adjusted to 8v, always changing, you can see the power supply