Huawei U8815 Maintenance Manual page 7

U8815
Maintenance Manual
Figure 9-19 Analysis of the U8815 memory interface ........................................................................................ 36
Figure 9-20 Transmitting and receiving circuit block diagram ........................................................................... 37
Figure 9-21 WCDMA IMT PA diagram .............................................................................................................. 38
Figure 9-22 WCDMA 850 PA diagram ............................................................................................................... 39
Figure 9-23 WCDMA PCS PA diagram .............................................................................................................. 39
Figure 9-24 GSM Quad_band_PA diagram ......................................................................................................... 39
Figure 9-25 UMTS IMT RX INTERSTAGE CHAIN diagram ........................................................................... 40
Figure 9-26 Diagram of dualband RF transmitting and receiving by using RTR6285A chip ............................. 40
Figure 9-27 Troubleshooting process for receiving failure ................................................................................. 41
Figure 9-28 Troubleshooting process for transmission failure ............................................................................ 43
Figure 9-29 Display screen circuit diagram 1...................................................................................................... 45
Figure 9-30 Display screen circuit diagram 2...................................................................................................... 45
Figure 9-31 Display screen circuit diagram 3...................................................................................................... 46
Figure 9-32 Troubleshooting process for no LCD display .................................................................................. 47
Figure 9-33 Motor circuit diagram ...................................................................................................................... 48
Figure 9-34 Vibration maintenance process ........................................................................................................ 49
Figure 9-35 Call reception circuit diagram 1 ....................................................................................................... 50
Figure 9-36 Call reception circuit diagram 2 ....................................................................................................... 50
Figure 9-37 Call reception circuit diagram 3 ....................................................................................................... 50
Figure 9-38 Call reception circuit diagram 4 ....................................................................................................... 51
Figure 9-39 7227A audio processing diagram ..................................................................................................... 51
Figure 9-40 Troubleshooting process for sound failure ....................................................................................... 53
Figure 9-41 Primary handset microphone circuit diagram .................................................................................. 54
Figure 9-42 Secondary handset microphone circuit diagram .............................................................................. 55
Figure 9-43 Troubleshooting process for sound failure ....................................................................................... 56
Figure 9-44 Headset circuit block diagram ......................................................................................................... 57
Figure 9-45 Troubleshooting process for no sound from the headset failure ...................................................... 58
Figure 9-46 SIM card circuit diagram ................................................................................................................. 59
Figure 9-47 Troubleshooting process for the UIM card detection failure ........................................................... 60
Figure 9-48 I/O connector circuit diagram .......................................................................................................... 61
Figure 9-49 microSD card connector circuit diagram ......................................................................................... 62
Figure 9-50 Troubleshooting process for micorSD card read failure .................................................................. 63
Figure 9-51 FM circuit diagram 1 ....................................................................................................................... 63
Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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