Motorola MotoRAZR maxx V6 Manual page 35

Motorola GmbH, Mobile Devices, CSS Center
Title: Troubleshooting-Guide MotoRAZR maxx V6
- If input power to PA is low it is most likely a problem with the TransAAM U500.
- If input power to PA is ok it is most likely a problem with the PA
If output power EGSM_OUT
U001 (do a visual check for misplaced parts around FEM U001).
GSM TX signals:
- TX_LB_IN
- IPC_BCM: mode switch between GMSK and EDGE. Currently BCM is associated
with GMSK mode and should be logic 0. In EDGE mode, IPC mode is selected and
should be logic 1:
- TX_LB_HB_IN: mode switch between LB and HB. LB is logic 0 and HB logic 1
- VRAMP: voltage that controls PA operation. If probed with an oscilloscope, you will
see signals close to a rectangular pulse of value 1.8V to 2.2V for max power output
- PAC_DET: power detector with voltage reading corresponds to VRAMP value
- TX_EN: logic signal that enables the PA
- GSM_TCXO: 26MHz clock for TransAAM
TX Supply voltages
- VRF_TX_2_775V
- BATT+
- LVDD
- JVDD
- QVDD_1_8
- VDDA_2_7
- VDDA_CP_2_7
- VDD_ACE_2_7
- VDD_TXRX_2_7
Repair Support Information
from PA is good the trouble is most likely related to a bad FEM
and TX_HB_IN: modulated input TX signal from TransAAM
Doc. No:
Version:
Date:
Page:
© Copyright 2003-2007 Motorola Inc. All Rights reserved.
Motorola internal use
TSG_3G_V6
1.0
23.07.2007
35 / 40
U800 itself.