ideacentre : mb la-d831p dead cpu mosfet

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • disorder
    Senior Member
    • Sep 2015
    • 154
    • france

    #1

    ideacentre : mb la-d831p dead cpu mosfet

    hello,

    i need some advise before plug this crapy thing on AC

    it is a all in one lenovo laptop, ideacentre with a la-d831p motherboard.

    this one come with no power , no led, dead state.

    open it and see that 12V power rail that goes to CPU power supply was totaly fried, and the two coils on it was blown. so remove this coils, but some solder mask on the rail and replace for test by 2 0ohm resistor (can't find the reference of PL smd)

    with this problem, one mosfet going to cpu was shorted : sm4377 on PQ1001 location. without this one no other short between pre and post mosfets.

    cpu seems to be fried too, so i had changed with another one. after press power button, the fan is spinning but no image on screen. just switch off

    the 2 0ohm resistors are blown and the mosfet i had replaced blown too (as the first time)

    remove this fet, replace and now no short mosfets.

    i replace àohm resistor by 22ohm resistor.

    now, when i mesure in diode mode, got 500 on the 12V side of the fet, and only 450 on cpu side without cpu

    when i put cpu, got only 0.9 and this raise nearby 3.

    if i push power button without cpu, span is spinning and got 12V on 12V side of all fets going to cpu.

    but i will not try with cpu without your advice.


    what do you think about this ?

    thank you

Related Topics

Collapse

  • Jane
    How do you test MOSFET in laptops ?
    by Jane
    I tried to use this method:

    Testing an N-channel MOSFET:

    Step 1: Discharge the Gate (turn off the MOSFET)
    Place the black probe (COM) on the Source (S) and the red probe on the Drain (D). The multimeter should show no continuity (high resistance or "OL" – open line).
    Then, touch the black probe to the Source (S) and the red probe to the Gate (G). This discharges any stored charge in the Gate, turning the MOSFET off.

    Step 2: Charge the Gate (turn on the MOSFET)
    Now, place the red probe on the Gate (G) and the black probe on the
    ...
    09-27-2024, 03:31 AM
  • Document Archive
    LENOVO IdeaCentre Q180 IdeaCentre Q D2700 Specification for Upgrade or Repair
    by Document Archive
    This specification for the LENOVO IdeaCentre Q180 can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the IdeaCentre Q180 boardview and IdeaCentre Q180 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download...
    09-12-2024, 03:36 PM
  • Document Archive
    LENOVO IdeaCentre Q180 IdeaCentre Q D2700 Specification for Upgrade or Repair
    by Document Archive
    This specification for the LENOVO IdeaCentre Q180 can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the IdeaCentre Q180 boardview and IdeaCentre Q180 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download...
    09-12-2024, 03:36 PM
  • Document Archive
    LENOVO IdeaCentre Y900-34ISZ IdeaCentre Y i7-6700K Specification for Upgrade or Repair
    by Document Archive
    This specification for the LENOVO IdeaCentre Y900-34ISZ can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the IdeaCentre Y900-34ISZ boardview and IdeaCentre Y900-34ISZ schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet,...
    09-12-2024, 02:30 PM
  • Document Archive
    LENOVO IdeaCentre Y900-34ISZ IdeaCentre Y i7-6700K Specification for Upgrade or Repair
    by Document Archive
    This specification for the LENOVO IdeaCentre Y900-34ISZ can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the IdeaCentre Y900-34ISZ boardview and IdeaCentre Y900-34ISZ schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet,...
    09-12-2024, 02:30 PM
  • Loading...
  • No more items.
Working...