Konka msd6i981btc movement
Publish: 2021-05-21 15:39:24
1. 1、 Analysis and maintenance: the output voltage of 3.3V and 24V of the power board is normal, and it is judged that the main board is faulty. Measure the 12V voltage output point on the main board, and find that the voltage at this point is 24V
the main board's u803 (mp1593) and its peripheral circuits form a 12V voltage forming circuit, which converts the input + 24V voltage into DC-DC and reces the voltage to 12V. After checking that there is no abnormality in the peripheral components of u803, replace it and start the machine, and remove the fault
it is found that the grounding area of the integrated block is too small when replacing the u803. In order to prevent it from being damaged again, the grounding welding area of the u803 should be expanded
2. The 24 V and 3.3 V at the P100 socket on the main board are normal, and there is no backlight power on signal, which indicates that the main board has been turned on, the main chip U500 (msd6i981btc) does not work normally, and the measured voltage stabilized power supply is normal. The fault of mbootu502 (25q16) is still normal, and it can not be upgraded by using force software. Finally, it is suspected that U500 is damaged or poorly welded, After repair welding, remove the trouble.
the main board's u803 (mp1593) and its peripheral circuits form a 12V voltage forming circuit, which converts the input + 24V voltage into DC-DC and reces the voltage to 12V. After checking that there is no abnormality in the peripheral components of u803, replace it and start the machine, and remove the fault
it is found that the grounding area of the integrated block is too small when replacing the u803. In order to prevent it from being damaged again, the grounding welding area of the u803 should be expanded
2. The 24 V and 3.3 V at the P100 socket on the main board are normal, and there is no backlight power on signal, which indicates that the main board has been turned on, the main chip U500 (msd6i981btc) does not work normally, and the measured voltage stabilized power supply is normal. The fault of mbootu502 (25q16) is still normal, and it can not be upgraded by using force software. Finally, it is suspected that U500 is damaged or poorly welded, After repair welding, remove the trouble.
2. Typical maintenance case:
fault phenomenon: the light does not start up fault
analysis and maintenance process: power on and test the main board power interface xs803, the 5 V pin is normal, the 7 V pin on / off control voltage is 0 V low level, and the 3 V pin has no 12 V output. Further test the power supply of the main chip n501 (msd6i981): 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. Upgrade boot program N506 fault is still, detect the main chip to DDR communication connection row resistance to ground resistance value, by comparing each data line to ground resistance value, found that the connection n501 C11 pin and n502 (DDR) T3 pin of this data line to ground resistance value, obviously larger than other normal resistance value. It is confirmed that the reason for the high ground resistance of this data line is: the C11 pin connecting to n501 is open circuit, the hole is filled with tin, and the test machine fault is eliminated.
fault phenomenon: the light does not start up fault
analysis and maintenance process: power on and test the main board power interface xs803, the 5 V pin is normal, the 7 V pin on / off control voltage is 0 V low level, and the 3 V pin has no 12 V output. Further test the power supply of the main chip n501 (msd6i981): 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. Upgrade boot program N506 fault is still, detect the main chip to DDR communication connection row resistance to ground resistance value, by comparing each data line to ground resistance value, found that the connection n501 C11 pin and n502 (DDR) T3 pin of this data line to ground resistance value, obviously larger than other normal resistance value. It is confirmed that the reason for the high ground resistance of this data line is: the C11 pin connecting to n501 is open circuit, the hole is filled with tin, and the test machine fault is eliminated.
3. Connect the upgrade board to view the print information, such as UART_ 115200 bist0-fail (Note: This indicates that the communication between the main chip and DDR fails) [] - 77 this kind of situation is more common, generally BGA false welding or poor plate. If there is no upgrade board, you can also directly test the resistance to ground of the main chip and DDR connection to determine whether there is a problem with the connection.
4. Hello, I'm glad to answer for you
fault phenomenon: the light does not turn on, =
analysis and maintenance process: power on and test the main board power interface xs803. The 5 V pin is normal, the 7 V pin control voltage is 0 V low level, and the 3 V pin has no 12 V output. Further test the power supply of the main chip n501 (msd6i981): 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. Upgrade boot program N506 fault is still, detect the main chip to DDR communication connection row resistance to ground resistance value, by comparing each data line to ground resistance value, found that the connection n501 C11 pin and n502 (DDR) T3 pin of this data line to ground resistance value, obviously larger than other normal resistance value. It is confirmed that the reason for the high ground resistance of this data line is: the C11 pin connecting to n501 is open circuit, the hole is filled with tin, and the test machine fault is eliminated<
fault phenomenon: the light does not turn on the fault
analysis and maintenance: led32is97n (4bom), led42is97n (4bom), encounter not turn on (no 12V) fault more, the fault point is in the main board fault, but most of the maintenance personnel can not repair
the maintenance method is described as follows: first, test the power supply interface xs803 of the main board. The 5V pin is normal, the control voltage of the power supply interface xs803 of the main board is 0V low level, and the power supply interface xs803 of the main board has no 12V output. Further test the power supply of the main chip n501: 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. It is judged that the main board fault is that the communication between the main chip and DDR is poor. Generally, the main chip n501 (msd6i981) is falsely soldered and can be re soldered. In addition, there is an open circuit in the communication connection between the main chip and DDR, and the open circuit holes are B16 and C11 pins of n501 (BGA package)
if you are satisfied, please click [adopt answer] on the right. If you have any questions, please click [follow up]
I hope my answer will help you, please adopt< br />
~ O(∩_ ∩)O~
fault phenomenon: the light does not turn on, =
analysis and maintenance process: power on and test the main board power interface xs803. The 5 V pin is normal, the 7 V pin control voltage is 0 V low level, and the 3 V pin has no 12 V output. Further test the power supply of the main chip n501 (msd6i981): 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. Upgrade boot program N506 fault is still, detect the main chip to DDR communication connection row resistance to ground resistance value, by comparing each data line to ground resistance value, found that the connection n501 C11 pin and n502 (DDR) T3 pin of this data line to ground resistance value, obviously larger than other normal resistance value. It is confirmed that the reason for the high ground resistance of this data line is: the C11 pin connecting to n501 is open circuit, the hole is filled with tin, and the test machine fault is eliminated<
fault phenomenon: the light does not turn on the fault
analysis and maintenance: led32is97n (4bom), led42is97n (4bom), encounter not turn on (no 12V) fault more, the fault point is in the main board fault, but most of the maintenance personnel can not repair
the maintenance method is described as follows: first, test the power supply interface xs803 of the main board. The 5V pin is normal, the control voltage of the power supply interface xs803 of the main board is 0V low level, and the power supply interface xs803 of the main board has no 12V output. Further test the power supply of the main chip n501: 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. It is judged that the main board fault is that the communication between the main chip and DDR is poor. Generally, the main chip n501 (msd6i981) is falsely soldered and can be re soldered. In addition, there is an open circuit in the communication connection between the main chip and DDR, and the open circuit holes are B16 and C11 pins of n501 (BGA package)
if you are satisfied, please click [adopt answer] on the right. If you have any questions, please click [follow up]
I hope my answer will help you, please adopt< br />
~ O(∩_ ∩)O~
5. Analysis and maintenance process: power on and test the main board power interface xs803. The 5 V pin is normal. The control voltage of 7 pin is 0 V low level. The 3 pin has no 12 V output. Further test the power supply of the main chip n501 (msd6i981): 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. Upgrade boot program N506 fault is still, detect the main chip to DDR communication connection row resistance to ground resistance value, by comparing each data line to ground resistance value, found that the connection n501 C11 pin and n502 (DDR) T3 pin of this data line to ground resistance value, obviously larger than other normal resistance value. It is confirmed that the reason for the high ground resistance of this data line is: the C11 pin connecting to n501 is open circuit, the hole is filled with tin, and the test machine fault is eliminated
analysis and maintenance: led32is97n (4bom) and led42is97n (4bom) have many faults of not starting up (no 12V), and the fault points are all on the main board, but most maintenance personnel can't repair them
the maintenance method is described as follows: first, test the power supply interface xs803 of the main board. The 5V pin is normal, the control voltage of the power supply interface xs803 of the main board is 0V low level, and the power supply interface xs803 of the main board has no 12V output. Further test the power supply of the main chip n501: 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. It is judged that the main board fault is that the communication between the main chip and DDR is poor. Generally, the main chip n501 (msd6i981) is falsely soldered and can be re soldered. In addition, there is an open circuit in the communication connection between the main chip and DDR, and the open circuit holes are B16 and C11 pins of n501 (BGA package).
analysis and maintenance: led32is97n (4bom) and led42is97n (4bom) have many faults of not starting up (no 12V), and the fault points are all on the main board, but most maintenance personnel can't repair them
the maintenance method is described as follows: first, test the power supply interface xs803 of the main board. The 5V pin is normal, the control voltage of the power supply interface xs803 of the main board is 0V low level, and the power supply interface xs803 of the main board has no 12V output. Further test the power supply of the main chip n501: 1.2V, 1.5V, 2.5V, 3.3vstb, 3.3V_ Normal was normal. Measure the reset output signal of pin 2 of reset chip n512: the power on moment is high level, then it becomes low level, and the effective reset signal of high level is normal. The 24MHz clock crystal oscillator on the main chip has been started and the oscillation frequency is normal. It is judged that the main board fault is that the communication between the main chip and DDR is poor. Generally, the main chip n501 (msd6i981) is falsely soldered and can be re soldered. In addition, there is an open circuit in the communication connection between the main chip and DDR, and the open circuit holes are B16 and C11 pins of n501 (BGA package).
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