Programme’s After Market Services NHP–4 Series Transceivers Disassembly & Troubleshooting Issue 1 04/99
NHP–4 Disassembly & Troubleshooting PAMS Technical Documentation CONTENTS Disassembly Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HD891 Baseband Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of baseband troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General Failures . . .
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Power Up and MCU Self tests Malfunctions Power Up Malfunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Troubleshooting Diagram; Power Up Malfunction . . . . . . . . . . . . . . . . . . Important Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.8304MHz clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Disassembly Instructions Remove the battery. Now remove two back cover screws and remove the back cover by lifting it away. 2 1 4 Then remove six chassis screws.
NHP–4 Disassembly & Troubleshooting PAMS Technical Documentation Remove the chassis by lifting. Turn around the chassis and open the display module a little. Open the display module connector by pressing both sides of connector and slide off the display module cable.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Turn chassis again and remove four chassis screws. 1 3 4 2 Remove the plastic shield and throw it away (it is disposable). Now you can separate the system module from the bottom shield by lifting it away.
NHP–4 PAMS Disassembly & Troubleshooting Technical Documentation HD891 Baseband Troubleshooting Overview of baseband troubleshooting Baseband oriented failures are typically discovered during flash and alignment. Before programming the flash memory, the phone is started in minimum mode and current consumption is measured. If current consumption is within acceptable limits and the MCU software version is successfully read via MBUS, the flash is then programmed.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Other Possible Failures Less likely failures may be: 1) Power circuit 2) Reset logic 3) Clocks 4) Charging circuit 5) BTEMP 6) BTYPE 7) Power to differential audio circuit and headset (VAHS) 8) RFTEMP 9) Watchdog circuit Troubleshooting Specific Sections Below describes in detail each of the main circuit sections. Circuit verification and troubleshooting can be performed by verifying the signals and voltages described in each section.
NHP–4 PAMS Disassembly & Troubleshooting Technical Documentation Check the,DSP (D707) supply voltage 3VD (3.15V) on pins 8, 11, 36, 39, 49, 64, 76, 87 and 90. 3VD (3.15V) is also fed to the DSP RAM (D709) to pin 11 and 33. Check the CDRFI (N703) supply voltage 3VD (3.15V) on pins 32, 33, 60, 62, 2, 6, 8 and 19. Check the supply voltages of the audio CODEC (N706). 3VA (3.15V) is fed to pins 41 and 42. 3VD (3.15V) is connected to pin 18. 4.8 Volt Linear Regulator The 4.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Watchdog The watchdog circuit is used to monitor whether the MCU software is functioning properly. The watchdog circuit will shut down the phone if it is not updated regularly by the MCU. Currently, the watchdog will expire and shut down the phone 9 seconds after the power–on button is pressed. Therefore, if the MCU fails to begin resetting the watchdog before the 9 seconds has elapsed, the phone will be shut down.
NHP–4 PAMS Disassembly & Troubleshooting Technical Documentation further tested to determine whether the address and data lines are connected and functioning properly by performing read and write cycles to various parts of the phone. This will be done at a separate test station. MBUS If the MBUS line is not working, the phone can not be flashed. MBUS signals must appear at MCU pins 66 (TXD) and 67 (RXD). For TXD they must also appear at pin 2 of V711 and pin 2 of V712.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Failures Current consumption failures Usually common to these types of failures is that phone can not be programmed or tested via MBUS. The most common failure is that phone takes normal current during startup and after a few seconds all circuits are powered down. The reason for this failure could be in power, clock or reset distribution of the phone.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Flash Programming OK, part 1 FLASH programming OK MBUS registration OK? YES Does LCD display turns ON? YES NO NO Check D706 pins 3,80 ASIC pins 130,86 3 Power stays on? YES Does LCD display turns ON? NO NO Check X701 Short circuits in data data lines. data line disconnected, VREF disconnected YES VBATT N500 pin 5,20 ? YES C507 OK? NO MBUS line X701 pin 5, Is 4.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Flash Programming OK, part 2 2 NO D706 pin 10 XSYS_RESET +3V after power on? YES 15.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Flash Programming OK, part 3 3 MBUS registration OK? YES Does LCD display turns ON ? YES D703 initialization (Factory Values Set) OK? YES 4 NO NO Check D706 and D703 interface D703 pin 18,19/D0,D1 +3V to 0V during r/w operations ? YES Change D703 Page 16 Issue 1 04/99
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Flash Programming OK, part 4 4 D709 /pin 11 is 12V while programming? NO Check X701/pin14 L700,C729,R748 R741 NO Check X701 pin 6 R736,R739,R764 C723 NO Check D706 pin 63 R725,R735,C721 YES D706 /pin 64/HOOK_RXD2 pulses during prog? YES X701 pin 7 /PHFS_TXD2 pulses during programming? YES D709 pin 10/RP +3V after power ON ? NO Check VCO_EN line at the D709 pin 10 for shorts and opens YES D709 pin 22/CE
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; PWR Button Fault Nothing happens when PWR button is pressed Check X701 NO N500 pin 10 +3V when VBATT is connected? YES NO N500 pins 5,20 VBATT voltage? YES Change N500 NO Check UI–conn.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Audio Fault Audio fault Microphone or earphone signal missing Microphone and earphone signal missing? YES N600 pin 19/CODEC_FS from D704 N600 pin 20/CODEC_MCLK from D704 D705 pins 29,37/CODEC_FS from D704 D705 pins 27,33/CODEC_MCLK from D704 YES N600 pin 25,24/MICP,MICN N600 pin 17/PCMOUT N600 pin 21/MICENX NO Microphone signal missing? corresponding pins of UI–connector NO Earphone signal missing? Issue
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Power Up Sequence Diagram VCTCXO G300 CDCONT 13 N201 CLK 15.36MHz 1 VRXS 4.5V 23 CDRFI N700 Square circuitry 63 CLK 15.36MHz VCO_EN VBAT 5.3....8V 4 5, 20 CHRGDET 21 11 PSL DETIN 12 16 N500 2 ON C507 14 24 8 XPWROFF 9 128 147 VL1 104 VL2 168 ASIC VL3 XSYS_RESET (3.15V) MCU_INT0 (3.15V) 121 VA1 98 MCU_NMI (0V) 69 10 MCU 77 D706 11 66 D704 VA2 XRESET MCU_CLK (15.36MHz) 2 VREF ON=3.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Repairing Instructions for Flash Faulty Units 1. When the phone doesn’t start (power off after 7seconds and probably no MBUS connection) check following things: 1VBATT is connected to the PSL_+3V(N500) 1XRESET 1VL1 rises to 3.15V is 3.15V 132KHz clock is running. 1VRXS(4.5V) is connected to the VCTCXO and the crystal frequency is 15.36 MHz 1XSYS_RESET signal rises to 3.15V 1MCU_CLK signal is 15.
NHP–4 PAMS Disassembly & Troubleshooting Technical Documentation Calibrate Battery Voltage (VBATDET)= 6.0V a) Check R505, R504 b) Check PSL_+3V(N500) pin 23 c) Check MCU(D706) pin 52 Calibrate Charge Voltage (VC)= 6.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Power Up and MCU Self tests Malfunctions RADIO UNIT CHECK Press power on Current consumption OK? NO See Power Up Malfunction NO See Self Tests Malfunction YES Run self tests OK? YES Call process Audio check OK Issue 1 04/99 Page 23
NHP–4 PAMS Disassembly & Troubleshooting Technical Documentation Power Up Malfunction Basically there are two different problems that could occur while powering up the phone. First, the current consumption is almost zero all the time. Probably the fault is at the power circuit PSL_+3V(N500). Check all PSL_+3V(N500) connections including VBATT line. Second, the phone’s current consumption is normal for 7seconds and goes to zero after that time. The reason for this is the watchdog. 1.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Figure 2 YES! Go to 1.2 / NO! Go to 1.11 1.11 Check VCO_EN is high (3.15V) CDCONT(N201) pin 23. 1.12 Check VCTCXO(G300) waveform at CDCONT(N201) pin 35 looks like Figure 3. Also check that VRXS line is 4.5Vdc at CDCONT(N201) pin 13. If all these conditions are meet check solder joints for shorts and opens, if they are OK replace CDCONT(N201).
NHP–4 PAMS Disassembly & Troubleshooting Technical Documentation 1.2 Check CDRFI(N700) pin 63. See Figure 4. Is there a 15.36MHz clock signal present? Figure 4 YES! Go to 1.22 / NO! GO to 1.21 1.21 Check this signal solder joints, if OK replace CDRFI(N600). 1.22 Check connections between ASIC(D704) and MCU (D706), especially ASIC(D704) pin 104 and MCU(D706) pin 69. If no clock is present and connection looks OK replace ASIC(D704). 2.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting MCU(D706). There should be rising edges time to time. If all these are OK and still XPWR_RESET is low replace the PSL_+3V(N500). 3.12 Check reset line for shorts and open between MCU(D706) and ASIC(D704), and between PSL_+3V(500) and ASIC(D704). If OK replace ASIC(D704). 4.0 Is 32KHz clock running? 1Check with oscilloscope if there is a 32.768KHz clock signal at ASIC(D704) pin 87. It should look like Figure 5. Figure 5 1YES! Go to 5.
NHP–4 PAMS Disassembly & Troubleshooting 1This table might help to locate power pins on main circuits. Circuit MCU ASIC Technical Documentation Number D706 D704 D704 DSP D705 CDRFI N700 CODEC N600 N600 FLASH D709 RAM D700 EEPROM D703 Pins Supply voltage signal 5,42 VL1 13,22,27,44,60,65,74,88,103 VL1 109,117,132,146,151,161,176 VL1 8,11,36,39,49,64,76,87,90 VL2 32,33,60,62,2,6,8,19 2,3 VA2 15 VL1 30,31,11 VL1 28 VL1 7 VL1 VL3 6.
NHP–4 PAMS Technical Documentation Disassembly & Troubleshooting Troubleshooting Diagram; Power Up Malfunction Start 1.11 Check VCO_EN is 3V NO NO 1.1 VCTCXO running OK? 1. MCU clock running OK? YES YES 1.12 Check Vctcxo sine wave and VRXS is 4.5V, if OK replace CDCONT (N201) 2. MCU’s supply voltages OK? Check solder joints, if OK replace CDRFI (N700) NO 2.1 Check PSL+(N500) VL1–line at pin 4 NO 1.2 Clock signal at CDRFI (N700) pin 63 ? YES YES 3. MCU reset signal OK? 1.
NHP–4 PAMS Disassembly & Troubleshooting Technical Documentation Important Information This section contains information that might be helpful while troubleshooting an HD881 phone. However it is not needed to troubleshoot power up problems. 9.8304MHz clock This clock is ”ON” when the phone is set to CDMA non–slotted mode and it is ”OFF” when the phone is set to AMPS mode. It is generated inside the CDCONT(N201) from the 15.36MHz.
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