例1 伊达HA881电话机,免提状态喇叭无声,查有关电路,发现免提开关附近两引线的铜箔中有一处色彩有异,用锐器划之,呈炭状,对其进行清除处理,把炭状物全部清除,试机正常。例2 伊达HA881(ⅩⅢ)电话机,振铃只有短暂的一声,外线再拨号无声。检查元器件正常,而话机挂机时断开外线测引线两端有200kΩ电阻且不稳定,仔细 Example 1 Ida HA881 phone, hands-free speaker state silent, check the circuit and found two switches near the hands-free copper foil in a different color, with sharp draw, charcoal, its removal , All the carbonaceous clean, test machine normal. Example 2 Ida HA881 (XIII) phone, the ring is only a short beep, the outside line dialing silent. Check the components normal, and disconnected when the phone hangs outside the test lead 200kΩ resistance at both ends and unstable, carefully