testing a transistor short to ground

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • jstiene
    Senior Member
    • Feb 2013
    • 148
    • USA
    #1

    testing a transistor short to ground

    Hello. I was hoping for some advice on what is probably a dumb question. On various sustain boards from Samsung, Panasonic,etc...they typically have a short between the transistor and ground. In help to determine if there is a common short on a sustain board (such as a LJ92-01698A or a LJ92-01763A)...is there a common pin that I should be checking to usually has become shorted?

    thanks!
    Tags: None
    • Nick's Tvs
      Badcaps Veteran
      • Jan 2014
      • 621
      • USA
      #2
      Re: testing a transistor short to ground

      Jstiene,
      When I open up a plasma tv the first thing I do, is check that my VA and VS lines are not shorted to ground. If they are, then I disconnect the Sustain boards from the power supply and from each other if that applies. Then test VS and VA pins again on each board. Once I know which board is causing the issue then I will go into a component level check.
      Was that the question??

        Comment

        Previous template Next

        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...
          2 Photos
          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...