LG KM710 Service Manual - Page 44

4. Trouble Shooting 4.1.2.3 FEM Pass wanted signal and include LNA matching circuit. U401 EGSM PCS DCS /GSM FL400 ESHS-C090SR GND5 GSM18001900_TX 16 11 GND4 GSM900_TX 15 13 GND3 14 9 GND2 GSM1900_RX2 6 GND1 GSM1900_RX1 7 5 GSM1800_RX2 4 GSM1800_RX1 3 VC2 GSM900_RX2 10 2 VC1 GSM900_RX1 12 1 ANT 8 22p FL400 L402 4.7nH L404 3.9nH C412 3p C414 3p C416 3.3p C418 3.3p 4.7nH L405 4.7nH L407 L406 18nH A1 PCSLNAI B1 PCSLNAIB C2 C1 PCSDCSGND D1 D2 DCSLNAI DCSLNAIB DCSG90GND E1 G90LNAI F1 G90LNAIB E2 G1 G90G85GND H1 G85LNAI G85LNAIB F2 G85GND G2 H2 GNDLNA_TX1 E3 TXON J2 GNDDMIXIN J1 DMIXIN DMIXINB 4.1.2.4 RF Transceiver (B6PLD) SAW Filter Bark Circuit Diagram Digital Interface to Baseband. Integrate LNA and VCO circuit. X400 U401 U403 U400 U402 FL400 SW400 4.1.2.5 DCXO C412 3p C414 3p C416 3.3p C418 3.3p L405 L407 L406 18nH 120 R403 5 1 120 R407 100ohm R406 68 R404 100ohm R408 C_VCCRF VCC_SYN C403 0.01u C409 22p C400 0.01u C406 3.9p C407 0.1u C404 3.9p B6 A6 GNDBBAD GNDRFVCO VCCBB VCCAD VCCRFVCO C5 QOUTB_QINB A5 C4 B5 A4 QOUT_QIN IOUT_IIN IOUTB_IINB GNDRFLO B4 A3 C3 VCCRFLO VCCMIX B3 GNDMIX D3 VCCLNA A2 PCSGND B2 A1 PCSLNAI B1 PCSLNAIB C2 C1 PCSDCSGND DCSLNAI D1 DCSLNAIB D2 DCSG90GND E1 G90LNAI F1 E2 G90LNAIB G1 G90G85GND H1 G85LNAI G85LNAIB F2 G2 G85GND H2 GNDLNA_TX1 E3 TXON J2 GNDDMIXIN J1 DMIXIN DMIXINB U401 R2A60167BG C6 A7 VCCRFSYN C7 GNDRFSYN CAFC B7 VCCVCXOR A8 BT_CLK C405 33nF C408 68p VCXTCXO B8 XOP A9 X400 FA-23H 4 3 1 2 R401 47K 26MHz XON B9 GNDVCXO_OR C8 VOUTEF2 VCCVCXO D7 C9 VOUTEF1 D8 VCCLOGIC2 D9 GNDLOGIC E7 CLOGIC1 F7 E9 VCCLOGIC1 E8 STROBE SYSCLK F8 RXTXDATA F9 G7 RXTXEN G6 TEST1 G9 CTRLEN G8 CTRLDATA CTRLCLK H9 C417 0.1u C419 0.01u VRIO L403 8.2nH U400 1 _OE 2A 3 GND VCC 5 4 Y SN74LVC1G125DRLR R402 1K C410 0.01u SYSCLK SLICER_IN C420 0.01u VCC_SYN VRIO DIGITALRF_DATA DIGITALRF_ENABLE DIGITALRF_RF_CS DIGITALRF_RF_DATA DIGITALRF_RF_CLK J8 TXOUTD VBAT_IN SYSCLKEN H8 TXOUTG GNDTXVCOD_B GNDTXVCOD VCCTXVCO H6 VCCTX2 J5 GNDTX2 G5 EAMPIB LDO_CONT TXBAND TXMODE F3 VCCTX1 FEMC1 G3 FEMC2 J3 VCCFEMC J9 H7 J7 J6 H4 H5 G4 H3 J4 C425 22p R409 100ohm C423 0.01u SYSCLKEN C_VCCRF RF Transceiver Circuit Diagram Produce RF and BB reference Clock - 26MHz Clock. R401 C408 68p C408 X400 VCXTCXO B8 XOP A9 X400 FA-23H 4 3 1 2 R401 47K 26MHz XON B9 GNDVCXO_OR C8 VOUTEF2 D7 DCXO Circuit Diagram Copyright © 2008 LG Electronics. Inc. All right reserved. Only for training and service purposes - 45 - LGE Internal Use Only