Blu DASH 3.5, Руководство по обслуживанию

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2.6 RF circuit
RF functional block diagram as following:
RF interface features:
◆
TX output chain controls
1) Multiple CDMA and UMTS PA on/off and range controls
2) GSM PA power control
3) 14-bit generic RF controller (GRFC) interface
◆
RTR6285A status and control
1) Multiple SSBIs
2) Tx enable and gain control
◆
Rx/Tx analog baseband interfaces
1) Dual Rx analog baseband interfaces support CDMA and UMTS diversity Rx plus
S-GPS
2) Tx analog baseband supports all phone transmission modes
3. Trouble Shooting
3.1 Fail to startup/power on
The following conditions may cause boot fail: battery low, battery connector is damaged or
bad welding, components bad weld/short-circuit or damaged
First, change a fully charged battery test, still startup fail, check battery connector ok or not, if
connector damaged change a new one;
Second, connect to DC power supply, if the boot process is no current, we should check
power key solder ok or not;
Third, if the boot current is very small and cannot maintain ,connect the power on test point to
GND, then check below voltage in sequence, VREG_S1
，
VREG_S2
，
VREG_S3_SP
，
VREG_L3
，
VREG_L7
，
VREG_L4
，
VREG_L12
，
VREG_L9
，
VREG_L14 ok not.