User Guide

Nokia Customer Care 6(b) - RF Troubleshooting Instructions
RH-37
Issue 1 07/04 Nokia Corporation Page 43
DC Supply Voltage Check
For a quick check of DC power supplies, refer to the diagram below. The RF power sup-
plies are generated in the UEM and can be measured either in the Small Signal Chamber
or in the Base Band Chamber.
The UEM output voltages can be measured at the respective resistors' / capacitors' pads
marked below in brackets, e.g. < C1234 >.
VR1
4.75 V [ 4.6V ... 4.9V ]
charge pump (VCP)
Tx modulator (Vcc_ModOut)
2.78 V [ 2.70V ... 2.86V ]
VCTCXO (+VCC)
digital interface (VDIG)
VR4
VR3
VR2
PLL prescaler (VPRE)
VR5
phasing dividers of Rx (VLO)
BB buffer (VDIG)
VR6
Rx Front End (VRF_RX)
16 mA [max. 20 mA]
VCO (VCC_VCO)
VR7
UEM
Triple band PA
VBAT
100 uA
bias reference (VB_EXT)
V
refRF01
TX buffer & EDGE ALCs (VRF_TX)
Bias & Rx CH filters (VF_RX)
2.78 V [ 2.70V ... 2.86V ]
RF controls (VPAB_VLNA)
2.78 V [ 2.70V ... 2.86V ]
100 uA
bias reference
(RXIINN, RXQINN)
V
refRF02
2.78 V [ 2.70V ... 2.86V ]
2.78 V [ 2.70V ... 2.86V ]
2.78 V [ 2.70V ... 2.86V ]
2.7 V [ 2.95V ... 4.7V ]
1.35 V [ 1.32V ... 1.38V ]
1.35 V [ 1.32V ... 1.38V ]
< C7516 >
< R7516 >
< C7519 >
< C7517 >
< C7521 >
< C7500 >
< R7511/C7516 >
< R2901/C2901 >
AND
< R2900/C2900 >
< C7510 >