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一部经人修过的HA81(Ⅱ)P/T型电话机相隔的两行按键“4”、“5”、“6”和“*”、“0”、“＃”音频、脉冲均不发号,发号键盘线路及导电橡胶无开路和接触不良,更换发号芯片HM9102D故障依旧。经检查,此故障是由于焊点搭锡引起与上述两行按键相连接的HM9102D的键盘输入脚②与④之间短路造成的。受此故障启发,笔者发现在许多按键电话中,当发号芯片的键盘输入脚C_1—C_4之间或R_1—R_4之间任意几脚存在短路时,则与这几脚相连的几列或几行按
A two-line buttons “4”, “5”, “6” and “*”, “0” and “#” keys separated by a serviced HA81 (II) P / T telephone without any pulses Fat code, issued a number of keyboard lines and conductive rubber without open and poor contact, replace the chip number HM9102D still the same. After inspection, this fault is caused by the solder joints take tin caused by the two rows of keys connected to the HM9102D keyboard input pin ② and ④ caused by a short circuit between. Inspired by this failure, I found that in many key phones, when the number of chips on the keyboard input pin C_1-C_4 or R_1-R_4 between any few short-circuit exists, then with these feet connected to a few columns or a few lines press