Dell E5550 LA-A911P R.1 ZAM80 - switch on for a second

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • rbvndonh
    Senior Member
    • Mar 2021
    • 162
    • B

    #1

    Dell E5550 LA-A911P R.1 ZAM80 - switch on for a second

    Hello,

    I try to learn laptop repair myself. I have some basic experience.
    Laptop is Dell E5550 LA-A911P R.1 ZAM80.
    Laptop switch on just for a 1-2 seconds and switch off. No self-restarts.
    I can switch on agin, but situation repeat.

    PL101 3.3V
    PL102 5V
    PL700 19.08V
    PL701 13.60V

    On rest coils 0V jumping up just for a while when i push power button.

    I found near pin 4 of PQ200 something like side-melted housing. I found that there is a short between pin 4 and 5 of this chip.

    My plan for tomorrow is to unsolder PQ200 and check also PQ201, because now it also show low resistance.
    How to check if PU200 also need replace and maybe it is no-brainer when PQ200 is faulty, then PU200 also?
    Maybe replace some small resistors/capacitors in it's area also, as i see there is PWR_SRC, so 20V on this line and can go straight on leg PU200?

    Plan for tomorrow also:
    I found some hint to check Measure voltages on pin 2, 4, 7, 8, 11, 12, 13, 18 of PU200 but don't know what values will be proper one?

    2- shall be 0,67V?
    4- VDDR ref. As DDR is 1,35V, so there shall be that voltage?
    7- 0,675V_DDR_VTT - but DDR is 1,35V, so what i shall get here?
    8- _1.35V marked on line
    11-5V
    12- 5V
    13- 1,35V
    18 -1,35V

    Thank you for hints.
  • rbvndonh
    Senior Member
    • Mar 2021
    • 162
    • B

    #2
    Re: Dell E5550 LA-A911P R.1 ZAM80 - switch on for a second

    No luck. It was just resin on PQ200.
    Any ideas?

    Comment

    • mon2
      Badcaps Legend
      • Dec 2019
      • 13837
      • Canada

      #3
      Re: Dell E5550 LA-A911P R.1 ZAM80 - switch on for a second

      Remove all power. Meter in resistance mode (2k is ok).

      Check each coil on the board for a low resistance value which may indicate a bad cap on that rail which could cause the power supply to shut off as observed. Low resistance = too high of a load and the current sense circuit will trip and disable the switching power supply. Some rails are low voltage and will be with a low resistance but check and post your findings.

      Comment

      • rbvndonh
        Senior Member
        • Mar 2021
        • 162
        • B

        #4
        Re: Dell E5550 LA-A911P R.1 ZAM80 - switch on for a second

        PL101 11,8KR
        PL102 22KR
        PL200 460R (with RAM module) 591R without RAM
        PL301 1,48KR
        PL500 44R
        PL700 40KR
        PL701 3,2KR
        I think that values are quite OK. CPU with 44R i5-5300U is OK?

        Same behavior on AC adapter and battery only.
        PU100 shall be OK, as there is stable 3/5V
        PU200 and PQ200 replaced, however between PQ200 and PQ201 connection there is only 550R to ground.
        PQ200 and PQ100 sometimes show short (after power disconnected) and sometimes not. Like some protection on board is switched on.
        Maybe some PU is malfunction? I hear of some PU700 poor quality soldering. Will look on that tomorrow..

        Edit: pic attached. One pin looks poorly soldered. The solder don't look best on one side of chip. Will resolder it tomorrow.
        Attached Files
        Last edited by rbvndonh; 01-13-2022, 02:03 PM.

        Comment

        Related Topics

        Collapse

        • Document Archive
          Acer Switch Switch V 10 SW5-017P Hybrid (2-in-1) V 10 Specification for Upgrade or Repair
          by Document Archive
          This specification for the Acer Switch Switch V 10 SW5-017P Hybrid (2-in-1) can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the Switch V 10 SW5-017P boardview and Switch V 10 SW5-017P 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,...
          09-06-2024, 05:30 AM
        • Natob82
          Micro Momentary Push Switch?
          by Natob82
          Great to be here! I'm a newbie here trying to find a "micro", momentary push switch to repair a Sony "clamshell" video walkman. This micro switch has long since discontinued by Sony, however I hope there are third-party switches of the same size and functionality that I might be able to source to play the same role. The purpose of this switch is to tell the video walkman that the user has activated the mechanical tape eject button, turning that physical action into an electronic signal that tells the tape transport mechanism to open so one can load or eject a video tape. I...
          12-21-2022, 05:22 AM
        • grimacelord
          NEC TurboExpress On/Off Power Switch Replacement Help
          by grimacelord
          Hello,

          I've been working on a NEC TurboExpress and I accidentally got the plastic inside the power ON/OFF switch too hot while doing other repairs and melted it. At first, it would still power on when sliding the switch, but you had to really press inward while sliding to get it to work.

          I removed the switch component and tried to gently melt the plastic back so it would work more reliably and all I managed to do was make it worse.

          I need to find a replacement On/OFF switch for this, but having some trouble figuring out which kind of switch I need....
          11-09-2023, 09:49 AM
        • SluggerB
          Help making a switch work the opposite way with a relay
          by SluggerB
          I have a very small float switch, I'm using in a very small tank. It only fits in one way. Link https://www.amazon.com/uxcell-Switch.../dp/B07DZ1J2GB

          I want the switch to be open when the water is high, and closed when the water is low. Unfortunately it works the opposite. And since this switch is designed to be underwater, it's all sealed up, there is no taking it apart or hacking it up.

          It will be driving a water pump, basic idea, when the water is low, switch closes, which turns on water pump, when enough water is in the tank, float switch floats,...
          02-07-2025, 07:57 PM
        • sam_sam_sam
          Modifying a 4 Position Universal Rotary Cam Changeover Switch LW26-20 for more cams
          by sam_sam_sam
          Panel Mount 4 Position 8 terminals Universal Rotary Cam Changeover Switch LW26-20 20A
          ( needs more cam circuits for the machine to work correctly again )

          https://www.ebay.com/itm/275321870186

          To
          3 Position 16 Terminals Universal Rotary Cam Changeover Switch LW28-20 20A
          ( not 4 positions but the right amount of cams circuits )

          https://www.ebay.com/itm/274660439950

          I going to take the 4 position cams selector switch and remove the cams that are on it and remove the cams off of the 3 position selector switch and swap them around...
          03-18-2023, 05:12 PM
        • Loading...
        • No more items.
        Working...