LG 47LB5D shuts down

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • inwo
    Member
    • Feb 2014
    • 11
    • USA
    #1

    LG 47LB5D shuts down

    Board EAX36781601A-F

    I'll buy a board if I can find one.

    This is my own set, so I don't want to give up on it.
    It failed while unattended. Hot smell and dead.

    The two big caps were bad. Low value/ high esr.

    Inverter MOSFETS shorted.
    PS MOSFETS shorted.

    4 diode packs shorted.

    After that set would run but PS MOSFET and Transformer ran hot.

    Quit completely after overheating.

    Last thing I found was 3 1uf/50 volt caps bad. Weird as they were all different brands.

    After that set and back light will come on for 2 sec when cold.
    PS output reaches about half voltage and shuts down.

    I don't have a way to ring transformer. Nor do I suspect it. Looks ok?

    Next step if I don't get help from someone, is find data on PS chip and try to figure out what keeps voltage down. Zener bad ?

    Any ideas?
    Tags: None
    Previous template Next

    Related Topics

    Collapse
    • Yanleb
      Panasonic TC-P50S1 shorted TXNSC1EDUU (TNPA4782AB) SC Board
      by Yanleb
      Hi every one. I just want to share the successful repair of my shorted Panasonic TNPA4782AB SC board.

      I don't usually do it but so many parts were shorted that I decided to buy the ShopJimmy repair kit instead of sourcing each components individually. Here is the list of components the kit contained, with a remark indicating if I needed that part or not :

      D608, good
      D618 RF101L4S, good (See warning 1 below)
      D619 RF101L4S, good (See warning 1 below)
      D865 RF101L4S, shorted (See warning 1 below)

      IC464 Inverter HA MC74HC1G14, shorted...
      03-09-2020, 12:00 AM
    • BalkanBoy
      Dead Razer Blade 14 2022, shorted CPU?
      by BalkanBoy
      Hi,

      today I got Razer Blade 14, Ryzen 9 6900HX and RTX 3070Ti.

      Laptop was completely dead. I found shorted CPU VRM mosfet, shorted 19V mosfet and blown battery fuse.

      I replaced it all, but still on CPU coil where mosfet was shorted I got very low resistance, near 0 ohms. On other CPU coils I got around 3 ohms.

      Laptop now raises voltage on whole board, but still nothing comes on the screen. CPU gets 0.7V on all coils except the shorted one. CPU gets only slightly hot, below 40 C.

      I removed coil and injected 0.7V, it draw around...
      09-27-2024, 12:44 PM
    • cappernicus
      Acer Spin 5 - Lenny_ICL (19771-1) -- Dead - PM_SLP_S3# held low
      by cappernicus
      Laptop model: Sp513-54n-74V2


      Testing power rails (separated by chip) reveals:

      19V_DCBATOUT - (active)

      5V_AUX_S5 - (active)
      5V_S5 - (active)

      3D3V_AUX_S5 - (active)
      3D3V_S5 27Ω - (good) - enabled by Nuvoton chip

      1D8V_VCCIN_AUX - (good) - enabled by 1D8V_S5 PG signal -- (dependent on 3D3V_S5)

      1D8V_S5 41Ω - (good) - enabled by 3D3V_S5 PG signal

      1D05V_VNN_BYPASS - (good) - enabled by 1D8V_VCCIN_AUX PG signal...
      09-25-2024, 05:19 PM
    • guizmo1967
      Dell Latitude 5501 LA-H181P shorted power rail
      by guizmo1967
      Hello,

      This is my problem:

      Laptop: Dell Latitude 5501
      Motherboard: EDC51 LA-H181P

      I have two power rails shorted to ground, +1.0V_PRIM and +3.3V_ALW_PCH. I removed solder on PJP302, +1.05VALWP (pad1) not shorted but +1.0V_PRIM (pad2) shorted.

      I also cleaned PJP38, pad1 not shorted, pad2 (+3.3V_ALW_PCH) shorted to ground.

      I measure the resistance of all the coils on the motherboard and they all were not shorted to ground except coil PL301 before I removed the solder on PJP302.

      I injected +1.05V - 2A...
      07-25-2023, 06:56 PM
    • kotel studios
      Intel D865PERL - no Vcore after replacing MOSFETs and MOSFET drivers
      by kotel studios
      Hi,

      Finally got time to fix this board up.
      At first it didn't give any POST codes. Turns out it was an unsupported Celeron D cpu. After dropping in an Celery 2.6gHz the CPU came out of reset with clock signal, but still no post codes. For a while it did work when I applied pressure to the ADP3168 chip, but on next reboot the MOSFETs started to burn. Then I left it as is for months.

      Now I came back prepared. Replaced the bad MOSFETs and the ADPxx18k drivers. Now I don't get any MOSFETs blowing up issues anymore. But sadly, the Vcore is missing. The whole VRM isn't...
      04-22-2025, 05:08 AM
    • Loading...
    • No more items.
    Working...