Carefully remove the "receiver", sichuan multimeter test indeed break, to repair shop to spend five yuan to buy a part put on troubleshooting. Carefully remove the screen and soft panel wiring plug. The first and bad suspected soft wire break phenomenon. Multimeter is a conduction test, one not found to have broken; After using alcohol to the plug connection of the two soft wire carefully erase after clean, black screen, eliminated panel key failure. Then, open button panel first, carefully and key-press panel of corresponding little round metal "array" (is made of adhesive joint) removed, with rubber will wipe away the dirt (don't use alcohol), reoccupy HB pencil (not 2 b pencil because carbon core is easy to have a tiny carbon particles is too soft, does not favor the keystrokes) will shed each contact small garden shape metal surface evenly. To increase the electrical conductivity, and then glued back intact (don't have the dislocation); 4, 6 key "glue" problem is ruled out, just like that.ttmservice manual download site