DV5-Board DAQT6AMB8F0 REV:F NO POWER

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • auzzie
    New Member
    • Jan 2012
    • 4
    • Cyprus

    #1

    DV5-Board DAQT6AMB8F0 REV:F NO POWER

    Hi to all.

    Need help with this laptop DV5 Board DAQT6AMB8F0 REV:F
    Found short on Mosfet PQ26 FDS4410A. Used the schematic I found on this forum and followed the short to ground from capacitor PC107 to coil PL12.

    Lifted one side of PL12 and the short to ground on Mosfet PQ26 is gone.
    Following the schematic next component is the capacitor PC161 which is short.
    Removed the PC161 tested it and it is ok but the positive pad on the motherboard is short to ground without the capacitor welded on.

    I have the following coil measurements with diode mode on:
    Without power
    PL7=0.524V
    PL8=0.382V
    PL9=0.448V
    PL12=0.013V

    With Power
    PL7=0.502V
    PL8=0.630V
    PL9=0.517V
    PL12=0.05V

    The laptop does not power on. When I press the power button I get power led on but when I release the button it goes off.
    I also have charger port led on.
    Attached Files
  • mon2
    Badcaps Legend
    • Dec 2019
    • 14023
    • Canada

    #2
    Re: DV5-Board DAQT6AMB8F0 REV:F NO POWER

    Please note that you CANNOT take diode mode tests WITH the power ON.

    Always perform DIODE and RESISTANCE checks with all power removed. No battery, no external power adapters.

    On this note, remove all power. Meter in resistance mode (2k scale or similar).

    Check for low resistance readings on each coil (large grey parts) to ground.

    Red meter probe on the coil pin; Black meter pin to ground (shield is ok).

    Searching for any low resistance to ground that may indicate a shorted cap that needs attention. Some low voltage rails are normally with a low resistance but share the readings.

    Do note that if the resistance is higher than the meter scale, the meter will report "OL" for over-limit - that is a good sign that the rail does not have a shorted cap.
    Last edited by mon2; 02-26-2022, 10:45 AM.

    Comment

    • auzzie
      New Member
      • Jan 2012
      • 4
      • Cyprus

      #3
      Re: DV5-Board DAQT6AMB8F0 REV:F NO POWER

      Thank you mon2,

      Have some measurements about resistance for the coils.
      PL7=1.438MΩ
      PL8=2.027MΩ
      PL9=2.465MΩ
      PL12=24.4Ω

      Obviously there is a short on PL12 to ground but it is not on any of the capacitors near PC161 or PC160 because I removed both and still have a short.
      Attached Files

      Comment

      Related Topics

      Collapse

      • playit
        450watt power supply 5v, 3.3v short to ground wire,in output rail ,connectors
        by playit
        hello everyone , working zebronics power suply 450 watts , 5v ,3.3v givin short to ground black wire, also in circuit at output, resistor was charred but shows right values , after removing resistors 39ohms, 51 ohms, there was no short , no continuity beeps with ground , but after replacing new resistors (now i am not switching it on) ,again short still exists . when i put bigger ohm resistor like 100k ohm , no short beeping sound comes , lower ohm resistor gives continuity beeps ,other big ones donest , as its a working psu , i am confused what to remove now or how to go further now .
        ...
        09-02-2023, 02:43 AM
      • MisterAIL
        820-00840 / No boot / PP3V3_G3H Short to ground
        by MisterAIL
        Hello everyone,

        Firstly sorry for my english, french guy inside.

        I brought a macbook pro A1708 - 820-00840 logic board, wasn't powering on.
        History is a day, nothing happened when opening the laptop.

        Nothing special inside, no corrosion, no liquid damage, never opened.

        First, with the logicboard alone on the desk, mesures are :
        5v017 and 0.000 amp. nothing else.
        Finding a short on the PP3V3_G3H_VR, but not on the PP3V3_G3H (0.540 on diode mode), PPDCIN_G3H_CHGR_R present (5,1 volts) PPVIN_G3H_P3V3G3H around 4.1 volts. PM_EN_P3V3_G3H...
        10-13-2021, 11:42 AM
      • triplefour
        Samsung UN55ES7003 has blown fuse on TCON and short to ground.
        by triplefour
        Samsung UN55ES7003
        made house call.
        red power led comes on, blinks twice, no display, no backlight, relay clicks, repeat.
        psu has self test feature.
        disconnected from mainboard.
        determined PSU ok BL ok.
        suspect mainboard.
        disconnecting tcon has no change on operation.
        markings on mainboard:

        BN97-06531P 0151
        BN94-06123R

        found and ordered replacement on ebay https://www.ebay.com/itm/394077328633
        for 54$

        second house call:
        with replacement mainboard, tv turns on, has sound,...
        07-13-2022, 03:53 PM
      • Prott
        PS5 - long screw damage, via to ground layer short?
        by Prott
        Hello dear Badcappers,
        I came across a PS5 that was longscrewed. The screw went through the HDMI IC (which I replaced + repaired the traces it damaged), however the screw also bend the board and slightly cracked it on the other side. It still seems like it could be fixable though as the area might not have lots of traces going through it (fingers crossed).

        Can somebody, please, measure their board and tell me if my assumption of an inner short between the via and ground layer is correct? These 3 pads have almost no resistance. I would like to make sure those are not some data...
        07-27-2024, 08:54 AM
      • DynaxSC
        Extreme High Current & Low Voltage Short Killer ??
        by DynaxSC
        Hi Folks

        I'm looking for a extreme high current short killer solution for a reasonable cost.

        I have an LGA1700 motherboard (ASUS PRIME Z790-P WiFi) where I exchanged the LGA socket already 3 times, and every time after the socket exchange I get a short of power supply lines VCORE (V variable) and VCCIN_AUX (1.8V).
        After taking off the socket, the shorts dissappear again.
        The soldermask on the socket is already partially demaged from the heat, so I have reconstructed the soldermask by manually painting the missing soldermask parts with a very small top of a...
        10-15-2024, 10:13 AM
      • Loading...
      • No more items.
      Working...