Sharp TM200 Service Manual - Page 39

CONFIDENTIAL 10. BACK LIGHT DOES NOT TURN ON. Is VBAT voltage applied to C738? YES Which back light does not turn on, Main or External? NO External display only. F702 is mounted improperly, or the fuse is brown. NO Is fuse (F702) in good appearance, mounted properly, and is there conduction? YES C733, C738, and L703 are defective. C Is back light setting for External Display set to On? YES Is CN705 in good appearance and mounted properly? YES Is the contact point of back light FPC clean? Is back light FPC properly inserted to CN705? YES Is 3 - 6 V applied between TP710 and TP705? Is 3 - 6 V applied between TP710 and TP706? Is 3 - 6 V applied between TP710 and TP707? Is 3 - 6 V applied between TP710 and TP711? NO Are C735, C791, C733, C738, C730, C731, R708 and R707 in good appearance and mounted properly? YES IC708 are defective. C NO NO NO NO YES Go to the setting as follows and set it to On: Settings Phone Settings Main Display Backlight Does it turn on? Not defective. YES CN705 is defectiv e. Back light FPC or CN705 is defective. NO Clean back light FPC and insert it again. Does it turn on? Not defective. YES Back light FPC is defective. NO C735, C791, C733, C738, C730, C731, R708 and R707 are defective. Is back light setting for Sub Display set to On? YES Is 3-6V applied between LED703 anode (A) terminal and LED704 cathode (K) terminal? YES LED703 and LED704 are defective. Go to the setting as follows and set it to On: NO Settings Phone Settings External Display Back light NO Does it turn on? Not defective. YES NO IC708 is defective or mounted improperly. TM200 1ADJUSTMENTS, PERFORMANCE CHECK, AND FIRMWARE UPGRADE 2 - 35