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CASIOfx-39型计算器是一种较典型的荧光数码管式函数型袖珍计算器.由于该计算器的电路比起普通型计算器来要显得复杂,内部元件排列也较紧凑,因此不少修理者和使用者感到检修较为困难.本文通过几个实际检修例子,介绍一些较复杂故障的检修方法,供大家参考. 1.故障现象:开机后按键送数正常,但不能进行+、-、×、÷等运算;而log、ln、??、sin~(-1)、cos~(-1)、tan~(-1)等键的功能却是良好的.经查+、-、×、÷等键的接触及连线等均无问题. 原因分析:在fx-39计算器中,38个按键及DEG、GRA、RAD、SD功能模式选择开关并成五根相应的输入公共线与大规模集成电路LSI(HD38111A)
CASIOfx-39 calculator is a more typical fluorescent digital tube type pocket calculator. Since the calculator circuit than ordinary calculator to appear complicated, the internal components are also arranged more compact, so a lot of repair And users feel more difficult maintenance. This article through several examples of actual maintenance, introduced some of the more complex troubleshooting methods for your reference. 1. Symptom: power button press the number of normal, but can not be +, -, × , ÷ and other operations, while the functions of log, ln, ??, sin ~ (-1), cos ~ (-1), tan ~ ÷ equal key contacts and connections are no problem. Analysis: fx-39 calculator, 38 buttons and DEG, GRA, RAD, SD function mode selector switch and into five corresponding input common line and large Scale integrated circuit LSI (HD38111A)