With the opening of local network analog phones , analog cell phone with its voice clear, wide coverage , low-cost advantages by consumers love , but because of analog phones into the country a long time , many models have entered the maintenance period . Here we offer a special tie to the Xinhua (NEC) P series phones use the programming test interface circuit , the circuit can fix Xinhua series phones (P388, P688, P688A , etc.) of all software failures, lift the handset locking , and Test mode to open its mobile inspection instrument with adjustments and maintenance. First, self- programming interface Component Selection : All components are no special requirements on the programming power analog phone connection plug is not easy to buy , it is proposed P688 charger (ie AC adapter ) plugs replaced . Actual production : without the use of printed circuit board , you can choose each component pin SMD IC will direct the appropriate use of wire bonding and then into the plastic box , after check, with the four leads ( lead length 10 cm is appropriate ) if Can not find a special plug , can be welded directly to the four leads to the corresponding mobile phone contacts . 2 , Xinhua (NEC) P series of analog mobile phone operating instructions Xiangjie maintenance apparatus used (more detailed instructions please visit my site http://839.126.com) Turn on the phone programming state : the self- maintenance test interface into mobile phone programming interface end , press the power key to power . At this point, the mobile phone screen will appear version information. MR # 01 into the test termination mode , display full screen . Use the following instructions before each of the implementation of this directive . MR # 02 out of test status to enter normal mode , the phone is receiving the call status . MR # 03 shows the 16 phone information to receive the channel used to read RSSI value . MR # 06 initialization mobile transceiver channel , while the timer reset . MR # 07 start firing channel , according to power supply ammeter and frequency meter reading can determine whether the normal firing circuit . MR # 08 closed launch carrier channel. MR # 09 X X X X # set the designated channel number . X said that the channel number . Effective range from 0000 to 2047 . MR # 10 X # to transmit power attenuation value placed back under the command value ( 0 ~ 7). MR # 11 disable the receiving channel . MR # 12 turn on the receiver channel , the handset can be heard rustling or system to send out the voice , signaling tone . MR # 16 launch continuous 8kHz tone . MR # 17 to stop launching continuous 8kHz tone . MR # 23 display phone software version information. MR # 24 Display phone electronic serial number 11 . MR # 39 master reset , this command can be used to clear the lock . Such as FL, PL, KEY-LOCK , etc. . MR # 69 XXXX # measurements from the command channel later RSSI value of each channel , indicating channel value . MR # 70 through the keyboard NAM programming , while the parameters of the system programming . MR # 86 to adjust the transmitting power mobile phone . MR # 87 instructions in the box to adjust the number of mobile phone signals . MR # 90 XXX # instructions and adjust the battery voltage A / D conversion value ( 0 ~ 255 ) . MR # 71 to enter the user number NAM1 programming . No programming instructions , not the number of restrictions on programming . MR # 78 # # all set to restore the original factory data . Programming times for cleaning and solve the boot display four dashes . Note : This operation will clear the user name NAM programming . Third , the software fault repair ( boot failure shows four horizontal resolution ) This failure occurs in the series machine frequently . One is the hardware causing the second is a software problem . Distinction is to boot several times , if a successful boot , it is hardware problem . Check the CPU pins welded focus , logic board and RF board connection seat contacts . Repair welding or cleaning solve the problem. Many times a normal boot if no disturbance was caused by internal data CPU software failure , the solution is as follows: Insert the phone end of this instrument programming interface , power button to turn on the display should show character , according to MR # 01, the display Full screen , press the MR # 78 # #, shutdown . Remove the inspection device, the boot can be .