Kenwood TS-990S Service Manual

Also see for SP-990: Instruction manual

Contents

TS-990S158TROUBLE SHOOTINGFault Diagnosis of the BGA (Ball Grid Array) IC■ OverviewThis flow chart will determine whether the BGA parts are faulty when the transceiver does not start normally, or the LCDscreen is blurry or has an unusual coloring.■ BGA partsApplication MCU (IC1, IC201), DDR2 (IC2, IC3, IC202, IC203)When the BGA IC is problematic, please bring the printed circuit board (X46-3390-01) in for service.● Checking power supply voltageChecking voltagePoints to be checked1.8V_1: L1 or L2013.3V_2: F11.2V_3: L2 or L2021.8V_4: CN2 (1 pin)3.3V_5: F2Power supply of each device is connected through the fuse or coil.[MCU: IC1]1.8V3.3V (Check whether F1 is problematic.)1.8V (Check whether F801 (DC-DC unit C/3)is problematic.)1.2V3.3V (Check whether F2 is problematic.)[MCU: IC201][DDR2: IC2, IC3]1.8V_1: L1[DDR2: IC202, IC203]1.8V_1: L2011.8V_1: L1, 3.3V_2: F1, 1.2V_3: L21.8V_4: F801 (DC-DC unit C/3), 3.3V_5: F21.8V_1: L201, 3.3V_2: F1, 1.2V_3: L2021.8V_4: F801 (DC-DC unit C/3), 3.3V_5: F2Normal voltageChecking for an abnormal point1.8V_1 has an abnormal voltage.[MCU: IC1 and DDR2:IC2, IC3]Remove L1 to check the voltage of the 1.8V_1.If the voltage becomes normal, the MCU (IC1) or DDR2 (IC2, IC3)is broken.[MCU: IC201 & DDR2: IC202, IC203]Remove L201 to check the voltage of the 1.8V_1.If the voltage becomes normal, the MCU (IC1) or DDR2 (IC2, IC3)is broken.3.3V_2 has an abnormal voltage.[MCU]Remove R747, L601, L403 and F601 (remove the flat cable ofCN651 and CN225, and the coaxial cable of CN652) to check thevoltage of the 3.3V_2.If the voltage becomes normal, the device connected after havingremoved the parts and flat cable, etc., is broken.o Check devices other than the BGA.If the voltage becomes abnormal, the MCU is broken.1.2V_3 has an abnormal voltage.[MCU: IC1]Remove L2 to check the voltage of the 1.2V_3.If the voltage becomes normal, the MCU (IC1) is broken.[MCU: IC201]Remove L202 to check the voltage of the 1.2V_3.If the voltage becomes normal, the MCU (IC201) is broken.1.8V_4 has an abnormal voltage.[MCU]Remove F801 of the DC-DC unit (C/3) to check the voltage of the1.8V_4.If the voltage becomes normal, the MCU is broken.3.3V_5 has an abnormal voltage.[MCU: IC1]Remove F2 to check the voltage of the 3.3V_5.If the voltage becomes normal, the MCU (IC1) is broken.If the voltage is not corrected, there is a problem other than the BGAparts.When an abnormalvalue is confirmed.When a normal value is confirmed.● Checking the clockChecking the SYS clockPoints to be checked26.000MHzMCU (IC201) side R30332.768kHzChecking the SYS_32k clockPoints to be checked26.000MHz26.000MHz32.768kHzNormal voltage(Amplitude: about 1.5V)MCU (IC201) side R369MCU (IC1) side R16632.768kHzMCU (IC1) side R95Normal voltage (3.3V)● Checking the Reset/LCDREQsignal inputChecking the MCU reset signalPoints to be checkedAnRSTMCU (IC201) side R3703.3V3.3VNormal voltageMCU (IC201) side R227MCU (IC1) side R1973.3VSYS clock has an abnormal.MCU (IC1): Replace the crystal oscillator (X1) and check thewaveform.MCU (IC201): Replace the crystal oscillator (X201) and check thewaveform.If the waveform is normal, the crystal oscillator is broken.If the waveform is abnormal, the MCU is broken.SYS_32k clock has an abnormal.[MCU][MCU]Remove R166 and R369 to check the waveform.If the waveform is normal, the MCU is broken.If the voltage is not corrected, there is a problem other than the BGAparts.The BGA parts are not broken.LCDREQ MCU (IC1) side R184 3.3VWhen an abnormalvalue is confirmed.When an abnormalvalue is confirmed.When a normal value is confirmed.When a normal value is confirmed.