Burning capacitors near Mosfet

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • the Benninger
    Senior Member
    • Nov 2022
    • 189
    • venezulan

    #1

    Burning capacitors near Mosfet

    Hi Folk's, Thhe machibe its Dell OptiPlex 3070 mini, don't power up, two capacitors near mosfet (PQ0) burning
    These that you see on camera are new replaced, I had doubts if it was the capacitor (pc64) but I changed both at once, it still results in the same thing, it does not activate the safety of the power supply, and anyway the machine does not turn on, I am limited I only got this boardview, All ideas are welcome, the positive side capacitors have 19V without oscillations

    Mobo: IPCFL-CG Rev.A00
    S/T: JX8CM63
    Attached Files
  • mon2
    Badcaps Legend
    • Dec 2019
    • 14120
    • Canada

    #2
    See attached. Remove all power. Measure the resistance to ground of these caps. One side will be ground. Other side should be a high resistance. Confirm this detail.

    Click image for larger version  Name:	burning_caps.png Views:	0 Size:	168.4 KB ID:	3298213

    Comment

    • the Benninger
      Senior Member
      • Nov 2022
      • 189
      • venezulan

      #3
      Thanks for answering, I confirm both capacitors have ground resistance ranging from 16kOm and if you hold the munitmeter for a while this resistance varies up to 24khom where it starts to slow down but continues to slow down
      Attached Files

      Comment

      • the Benninger
        Senior Member
        • Nov 2022
        • 189
        • venezulan

        #4
        There is another thing, I mentioned before when I created the post, that line that feeds the circuit has 19V without fluctuation, but the schematic you show me tells me that there should be 5V, you help me understand it mon2 thanks u

        Comment

        • the Benninger
          Senior Member
          • Nov 2022
          • 189
          • venezulan

          #5
          Disassemble the capacitors, one is 11 and the other 10.54uF, resistance on the positive rail without the capacitors is 25K

          Comment

          • the Benninger
            Senior Member
            • Nov 2022
            • 189
            • venezulan

            #6
            nice day mon2 u could read the data that is posted you I think you lost the thread I'm still interested in help can you take a minute out of your day to help me? I appreciate it. Have a very good day.

            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
            • 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
            • dragon3x
              After updating motherboard capacitors, what to do next (Asrock K7VT2, SOLTEK SL-75FRN2L)
              by dragon3x
              Hi, I have some 32 bits computer motherboards that need repair, as they fail to
              power on.

              Here are some examples :

              (N.B. "capacitors" indicated here are electrolytic capacitors located in the onboard
              switching supply area).
              (N.B. #2 : I could not find a 3300 microF aluminum-polymer with a higher voltage
              than 6.3 V.)

              1 - Motherboard #1 : this is an Asrock K7VT2 (socket A) that still works well. To put it on test
              I replaced capacitors with aluminum-polymer.
              3300 microF/6.3 V. x 4 replaced by 3300 microF/6.3 V. (KYOCERA...
              03-21-2025, 02:46 PM
            • 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...