Samsung SCH-A302 Service Manual page 14

SCH-A302
Trouble Shooting
(3) No.3 : 24108167813 - Tx Power Problem
- All TX path is good from RFT 3100 to Mixer input port.
- Mixer output is lower than normal status.
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- 1 local and operating voltages are ok.
- TX AGC ADJ voltage is too low.
- Estimated factor: Chip capacitor (C203) which connect to TX AGC ADJ
voltage line C203 Replace ok.
(4) No.4 : Tx Power Problem
- All TX path and voltages are ok from Duplex input to RFT3100 input
- CELLA_OUT (-pin#17) is ok, But U201 RF_IN (-pin#2)is not good.
- Estimated factor : F201 Replace ok.
(5) No.5 : 24108146584 When touch MSM, RX RSSI value has lost.
- All RX path is good from Duplex to Mixer input port .
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- 1 local & TCXO did not oscillate.
- TCXO upper case pushed then case and inside components were short when B'D is twisted.
Estimated factor : TCXO After replace TCXO It working ok.
(6) No.6 : 24108221088 - Problem with display (When power on, display was abnormal working)
- LCD and neighbor patterns are ok.
- Estimated Factor: Broken data which is in E2PROM. Data Rebuilding OK
(7) No.7 : 24108134768 - RX problem (No SVC)
- Handset doe not acquire SVC then searching CH repeat very quickly.
- All RX value is good at Rx Part Check Point.
- Ec/Io value (in debug screen) is bad.
- Estimated factor : MSM does not decode receiving signal.
(8) No.8 : No Power on (Can't not power on)
- X501 Sleep X-tal (32.768 MHz) is O.K
- V_DC 3.0V is O.K
- CHIP X8 No output IFR #38
- TCXO_N No output IFR #37
- TCXO Not oscillator Pin # 3
- TCXO crack : TCXO replace O.K
(9) No.9 : 24108233382 - ESN INVALID
- ESN No was broken : 0000000
- ESN data at E2PROM was broken caused ESD or Electric shock.
- E2PROM replace and rewriting ESN number.
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