How to check for short circuit

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • arieshenri
    Member
    • Jul 2011
    • 10

    #1

    How to check for short circuit

    Hi Guyz,

    I have a short circuit problem. When adapter plugged in the voltage of the jack adapter messed up. But when I took off NIKOS P2003EVG (P-Channel Fet Enhanced), the voltage going in is good.

    The questions is how to to check for the faulty components? or how to check the + or - shorts? Example in capacitor? or in transistor ?

    Anyone can help me please.. i have both digital multi meter and analog multi meter...

    schematic diagram of the laptop also have...
  • severach
    Badcaps Legend
    • Aug 2007
    • 1055
    • USA

    #2
    Re: How to check for short circuit

    That MOSFET has many pins that are supposed to be shorted so download the P2003EVG datasheet and test the pins that aren't supposed to be shorted. Keep in mind that if you charge the gate right then the part will appear shorted from Gate to Source even though it is functioning correctly. Read up on MOSFET testing because they are a bit trickier to test than BJT transistors.

    Then test the pads on the board to see if they are shorted. If the MOSFET isn't shorted and the pads are then you need to look farther down the line.

    I test for shorts on the DMM diode scale. Short the leads to see what a short is supposed to read on your DMM. Other people test with the ohm scale.

    A short is a short whether in our out of circuit and a shorted part produces phantom shorts in all parts that are in parallel so don't go pulling parts until you've tested a lot. Knowing what all parts show as shorted helps give you an idea of what to pull first.

    Ceramic and Tantalum SMD caps are good places to check for shorts.
    sig files are for morons

    Comment

    • momaka
      master hoarder
      • May 2008
      • 12170
      • Bulgaria

      #3
      Re: How to check for short circuit

      Originally posted by severach
      Keep in mind that if you charge the gate right then the part will appear shorted from Gate to Source even though it is functioning correctly.
      You mean Source and Drain?

      With the gate not charged, some MOSFETs may also show a diode reading between Source and Drain (since Body is usually tied to Source). If I remember correctly, for N-type MOSFETs, the diode reading will appear as if the Drain is the cathode and the Source is the Anode. For P-type MOSFETs, it's the other way around.

      If the Gate is charged as severach mentioned, then you may get a short-circuit between Source and Drain rather than a diode reading.

      Comment

      • severach
        Badcaps Legend
        • Aug 2007
        • 1055
        • USA

        #4
        Re: How to check for short circuit

        Yep, that would be source and drain. The body diode always conducts but not as a short unless burned out.
        sig files are for morons

        Comment

        Related Topics

        Collapse

        • jordanaudio1
          Samsung TV UN60KU6270F power supply
          by jordanaudio1
          Trying to learn electronics repair as a hobby. I have no formal training in electronics, circuits, etc. Everything I know, which isn't much, has been learned from watching youtube videos, reading books, forums, etc. This means, sometimes I have a hard time understanding and interpreting what's important when I look at datasheets, and such.

          My brother has a TV that I'm working on now. He said he was watching it, he heard a loud pop and it went off. I used my DMM to check the fuse, it was blown. From watching lots of hours of electronics repairs on youtube, I figured that was just a...
          07-07-2025, 07:38 PM
        • Geeker007
          9th Gen Dell Optiplex Micro PC motherboard repair: Short Circuit?
          by Geeker007
          Hi All, I have a 9th Gen Dell Optiplex micro PC motherboard which doesn't power on. When I connect the motherboard with power adapter, it goes into safe mode and turns off. So from info I have gathered online, it looks like there is a short circuit on the motherboard. So can you guys help me with figuring out the issue?

          I am new to electronics repair, so my queries could be naive but I am ready to learn.

          So I have a multimeter and a solder with me. But I can try to get a variable voltage power supply with a thermal camera as well. From what I seen online, best way is...
          01-28-2025, 03:31 PM
        • howardc64
          QN75QN85BAFXZA no backlight
          by howardc64
          2+ year old TV with many (720? 65" version has 720) mini LED dimming zones. TV boots, has sound, panel picture can be seen with flashlight. No backlight. No TV model sticker on rear panel (Maybe Samsung service removed it, read below). Found the model # through the PSU and zoned LED driver board numbers.

          PSU has a click near LED output circuit at 1 second interval, sounded like the 4x barrier rectifier area. Protective pastic liner under PSU shows heat signature on the Schottky Barrier Rectifier in this circuit. Found a shorted diode (2 diode per rectifier, failed rectifier labled...
          07-03-2025, 05:08 PM
        • fab13
          Nintendo Switch lite charging chip heats up and does not short circuit
          by fab13
          Hello everyone


          Small technical problem on a Nintendo Switch lite
          Here's what I noticed: the USB port has been damaged internally, with a short circuit on the power supply line to the small fuse.

          After replacing the USB connector, the short circuit went away and I can't see any other short circuit in the whole motherboard.

          When I charge the console, it seems to be charging: I get 15 volts and an amperage of 0.450 A.

          Then, after a while, the amperage increases to 1.1 A and the BQ24193 charging chip starts to heat up, as evidenced...
          09-16-2023, 04:59 AM
        • Tarot Superstars
          Short Circuit tester
          by Tarot Superstars
          Hello.
          I have seen a short circuit tester made with 3 * 9V batteries, a voltage limiter component and a resistor connected to the probes of a multimeter.
          The theory is that the meter becomes sensitive enough to read very low resistances and the lowest resistance to ground on a circuit is likely to be a short circuit in that area.

          Link
          The Amazing $1 Short Finder Upgraded! Convert ... - YouTube
          https://www.youtube.com/watch?v=0eixDdCpiO4

          My multimeter isn't normally sensitive to very small resistance, but when I put a 1 mega ohm resistor...
          09-25-2023, 09:11 AM
        • Loading...
        • No more items.
        Working...