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一台三星T108手机,故障现象较为少见:即合盖时经常不能拔打电话,如果打开翻盖,每次拨打均能顺利接通。仔细检查该机,一无进水,二无摔痕。初步分析该故障多为软件资料错乱所致。重写软件,故障依旧,难道接收电路有问题?仔细排查,未发现问题。检查磁控开关SW801及其线路,正常。因为合盖与打开翻盖时电流不同,难道中频IC有问题?更换中频IC,待冷却后试机,故障仍然存在。试更换13MHz、电源IC,未果,用热风枪将带胶CPU取下,更换一块新的CPU,试机,结果大失所望。此时维修陷入困境。此时该换的元件基本都换了,只剩下实时时钟32.768kHz晶振,因为手机进入待机状态(睡眠状态)时,主时钟晶体停止工作,转为实时时钟晶体工作,若它不正常会影响信号。更换32.768kHz晶体,手机恢复正常。
A Samsung T108 phone, the phenomenon of the more rare fault: that is often closed when the lid can not make calls, open the flip, each call can be successfully connected. Carefully check the machine, no water, two no drop marks. The initial analysis of the fault mostly due to software information disorder. Rewrite the software, the problem remains, do not receive the circuit? Carefully investigated, did not find the problem. Check the magnetic switch SW801 and its line, normal. Because the cover and open the current when the flip is different, is there a problem with the intermediate frequency IC? Replacement IF IC, to be cooled after the test machine, the fault persists. Try to replace the 13MHz, power IC, unsuccessful, with a hot air gun will take the glue CPU removed, replace a new CPU, test machine, the result disappointed. At this point maintenance trouble. At this point the replacement of the basic components have changed, leaving only the real-time clock 32.768kHz crystal, because the phone into the standby state (sleep state), the main clock crystal to stop working to real-time clock crystal work, if it does not affect the normal signal. Replace 32.768kHz crystal, the phone back to normal.