Alienware la-d751p gpu or mosfet?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • xxphgpxx
    New Member
    • Nov 2021
    • 2
    • Usa

    #1

    Alienware la-d751p gpu or mosfet?

    Quick disclaimer, I am nowhere near being able to fix any broken hardware or will I attempt to fix this myself. I just want to diagnose this as much as I can to see if it is even repairable (before i pay someone just to tell me it's not fixable).

    This is an alienware 17 r4 i bought for spare parts like ssd, hdd, memory, wifi etc. the laptop does not turn on and the charger turns off (safety mode) as soon as it's plugged in to the laptop. (Short to ground?)

    Opened the laptop and found the Current Sense Resistor has an excess solder, thinking someone has already attempted to inject voltage into this. This resistor beeps on the continuity mode.

    Measurements.

    Capacitor (positive side) to cpu vrm: 26ohms, 26ohms, 28ohms, 28ohms, 28ohms

    Capacitor (positive side) to gpu vrm: 24ohms for all i believe

    Ground to cpu vrms: 4ohms

    Ground to gpu vrms: 0 ohms

    2 mosfets circled in yellow are shorted and beeps with continuity and reads 0 ohms.

    Could the mosfets be the culprit?
    Ty
    Attached Files
  • ktmmotocross
    Boardkiller
    • Feb 2014
    • 3575
    • slovakia

    #2
    Re: Alienware la-d751p gpu or mosfet?

    inject 1V 10A+ and check what is heating

    Comment

    • adamski1952
      Senior Member
      • Oct 2021
      • 93
      • england

      #3
      Re: Alienware la-d751p gpu or mosfet?

      Maybe i'm wrong but those look like bios chips to me.

      Comment

      • ktmmotocross
        Boardkiller
        • Feb 2014
        • 3575
        • slovakia

        #4
        Re: Alienware la-d751p gpu or mosfet?

        Originally posted by adamski1952
        Maybe i'm wrong but those look like bios chips to me.
        yes they are

        Comment

        • Simplebeans
          Senior Member
          • Sep 2021
          • 130
          • UK

          #5
          Re: Alienware la-d751p gpu or mosfet?

          Originally posted by ktmmotocross
          yes they are
          How did you test the mosfets were shorted?

          Comment

          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
          • chestercc
            Alienware M18x Shorted CPU Mosfet
            by chestercc
            I've got an old Alienware M18x R1 which shorted out the charger whenever it was connected. Tracked down the short to two shorted caps and burned CPU power controller caused by a shorted mosfet on the CPU's graphic power supply.

            I've replaced the faulty mosfet, two shorted caps and the CPU Power controller (NCP6151S52MNR2G).

            Issue is now whilst there is no short if I attempt to power the system on the fans spin for a couple seconds there are no lights and no further action - the PCH is heating up but there is no CPU power coming out but there is an enable signal...
            07-16-2022, 06:05 AM
          • Nooy
            VGA MOSfet permanently shorted and loss of MOSfet pad
            by Nooy
            Hello everyone, I recently found this badcaps site and super Learn Electronics Repair youtube channel. And I wanted to learn how to troubleshoot power supplies and VGA cards and how to practice soldering, since I already have a properly defective piece of them. I am currently trying to solve two problems:

            I have a Gigabyte GV-RX460WF2OC-4GD type card. I managed to find the faulty MOSfet (AON6414A) on it, which I replaced. The card starts up, but after about half a minute, the MOSfet in the same position will be shorted again. Is it possible that the PWM controller driving the MOSfet...
            02-14-2024, 02:26 AM
          • AppleLover123
            Asus X712EA 3 volts after the first mosfet
            by AppleLover123
            Hey guys,

            i have a asus motherboard here and as the title says after the first mosfet (in the picture) there is nothing more than 3.15v.
            I injected 19v and max. 1 amp at the charging port and there is not voltage drop or smth. It's just taking 19v and 1 milliamp.
            Then i tried to inject 19v and max 1amp after the current sensor and there it first takes 19v and 4 milliamps and after 2 seconds it is taking nothing (no current).
            I measured on the coils on board everything seems fine. Also the main power rail is not shorted (infinite resistance).
            Now i thought something...
            12-15-2024, 07:49 AM
          • MicroSMD Lab
            ASUS ROG Zephyrus GPU Mosfet repeat failure
            by MicroSMD Lab
            The board number is GU502DU. I repaired this a couple weeks ago and it came back with the same issue, same mosfet failed (PQH9201). I'm hoping that the GPU was spared this time.
            I used the same replacement part (purchased from Mouser) and I'm certain the soldering was done properly since it took just as much effort to remove as before. What could cause this same mosfet to fail? I'm thinking if it was unsuitable then the others would fail too. I looked for similar failures on YTube and the mosfet was replaced with AOE6930 in one instance and AOE6932 in the other but it's possible that the...
            01-10-2024, 06:36 AM
          • Loading...
          • No more items.
          Working...