VX2255wmb will not powerup

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • fennec
    New Member
    • May 2008
    • 9

    #1

    VX2255wmb will not powerup

    Hi,

    I got a dead VX2255wmb from work. It received a snowball and it seems fuses are dead. My multimeter is dying, I ordered a new battery. I can check for continuity but it will power down if I try to check ohms values.

    I changed a SMD fuse at the back of the PSU card but it still didn't powered up. I found an other fuse on the front, I think it's the one referred as F103 on the card but I scratched the writing while removing the glue.

    It seems the main fuse is a regular resistor but I'm not sure I read the rating correctly, 10 ohms +/- 20% (second picture), is it equivalent to the spare on I found (first picture) ?

    Thx for your help !
    Attached Files
  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #2
    Re: VX2255wmb will not powerup

    The first picture shows Brown Black Black Gold = 10 Ohms 5%
    The second picture shows Brown Black Brown Gold = 100 Ohms 5% unless the color in the picture is not clear.
    I never use fusible resistor larger than 10 Ohms.
    Can you please show good picture of the bottom side?
    There should be a soldered in main AC fuse close to the AC inlet, I think it is the small rectangular box on the left of the AC inlet.
    You should also Ohm out the MOSFET mounted on the heatsink close to that fuse you taken out.
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment

    • fennec
      New Member
      • May 2008
      • 9

      #3
      Re: VX2255wmb will not powerup

      Hi budm,

      The first picture is the spare resistor I have, colors are indeed Brown Black Black Gold Brown ( 1 0 0 * 0.1 = 10 ?).
      The second picture is the fuse I removed, colors are Brown Black Brown Gold Black (1 0 1 * 0.1 = 10.1 ?). The other side of the resistor is very damaged, the colors can only be seen on this angle.

      I forgot to tell that I checked the fuse next to main, it is OK. When I plugged the monitor to check, the big capacitor was charged.

      I checked the MOSFET, I read 700 between Gate and Drain, is it enough ?

      Thx for your quick reply !

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA

        #4
        Re: VX2255wmb will not powerup

        Unless the resistors are 1% type, it does have 5 color bands, but it looks like MOX fusible resistor type. Please see Resistor color code.
        You need to check S ource and Drain.
        We need to bottom side of the board so we can see ho that burnt out resistor is connected. Is the resistor connected to the Source and Negative lead of the Main DC filter cap? If it is, then more likely to be 10 Ohms resistor 1% type.
        Attached Files
        Last edited by budm; 03-12-2012, 09:23 AM.
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment

        • fennec
          New Member
          • May 2008
          • 9

          #5
          Re: VX2255wmb will not powerup

          I thought it was different reading since both resistors are 5 and and not 4 bands.

          I checked Source and Drain also, it was around 700 ohms. Only Gate and Source was "short".

          I'll post a picture of the back this evening when I'll be back from work.

          Thx !

          Comment

          • budm
            Badcaps Legend
            • Feb 2010
            • 40746
            • USA

            #6
            Re: VX2255wmb will not powerup

            I would check the MOSFET out off the board, 700 Ohms does not sound right al all, but dead short Gate and Source? You may be reading the shorts in the output section of the IC that drive the Gate also. Remove the MOSTFET and measure the Gate connections to Source to see if it read shorts or real low Ohm.
            Never stop learning
            Basic LCD TV and Monitor troubleshooting guides.
            http://www.badcaps.net/forum/showthr...956#post305956

            Voltage Regulator (LDO) testing:
            http://www.badcaps.net/forum/showthr...999#post300999

            Inverter testing using old CFL:
            http://www.badcaps.net/forum/showthr...er+testing+cfl

            Tear down pictures : Hit the ">" Show Albums and stories" on the left side
            http://s807.photobucket.com/user/budm/library/

            TV Factory reset codes listing:
            http://www.badcaps.net/forum/showthread.php?t=24809

            Comment

            • fennec
              New Member
              • May 2008
              • 9

              #7
              Re: VX2255wmb will not powerup

              Those readings might be because of the dying battery of my multimeter, I'll unsolder it this evening and do the readings.

              Comment

              Related Topics

              Collapse

              • corrize
                A funny fuse story – Lumix LX100 II
                by corrize
                Hello, I disassembled this dead camera, and found this WTF… Two fuses soldered one above the other !
                I was pretty sure nobody touched it before, but that can't be from factory. There is flux, and capacitor is probably missing.
                The other weird thing : the fuses are « G » fuse : (0.75A – 8V), seems very low. The original fuse should be « O » : (32V 2,5A).
                There is « O » mark beside. All fuses have the same mark letter on main board. So, I can deduce it's a « O » fuse.
                And this correspond to the issus I saw : when I plug the battery, I measure the voltage dropping...
                10-19-2023, 09:58 AM
              • jesterace
                Samsung UE46ES8000 Blown fuse but no other signs of short
                by jesterace
                Hi I wonder if anyone might be able to steer me in the right direction. I have this Samsung UE46ES8000 TV and it went bang during use. The main fuse on the PSU board is open. I've checked every diode/mosfet/transistor I can see and nothing appears to be short to cause the fuse to go. The DC output of the bridge rectifier is not short either. I've seen online that some of these models are known for having their PFC mosfet or other mosfets shorting and blowing the fuse but i'm not seeing that here. If anyone aware of these models having any issues to cause this? I'm reluctant to just replace the...
                09-11-2024, 03:14 PM
              • narf
                Epson EB-U42 projector / Caps with 0.7 ohms ?!
                by narf
                hi all,

                first of all: i'm a (motivated) newbie, so please forgive me any stupid question i may or may not ask

                i'm currently repairing a projector: Epson EB-U42 that doesn't start (no lights, nothing).

                what i've found so far:
                - the PSU does its job and supplies 12V to the mainboard via the connector.
                - shortly thereafter, there is a mosfet (TS420-600B) where i can test 12V on the one side (in the data sheet this side is called Anode), Gate 0V, Kathode shorted to ground
                - not far away, there's the first cap with a resistance of 0.7 ohms....
                07-02-2024, 03:53 PM
              • jshhh
                Help replacing fuse on my Mimaki CJV300-160 vinyl printer
                by jshhh
                Hi guys,

                I'm inexperienced with electronics repairs, I've done a little bit of soldering caps and whatnot, but i have a blown fuse on this mimaki printer I got which I have bought a replacement for.

                How do I remove this type of fuse (see picture)...it kinda looks like it would pull out of that bracket but it didn't come at first pull and I didn't want to brute force it incase it's soldered on there like most of the rest of the components.

                Anybody know how to remove this type of fuse?

                (The fuse is toward the bottom of the image labeled F2)...
                06-17-2025, 01:35 AM
              • Babbar
                Argon SA1 audio amplifier power-supply - fuse blown after fixing the short?
                by Babbar
                I found a project in the electronics trash yesterday. A nice Argon SA1 audio amp with some electrical issue. Took it apart and saw that the 4A250V fuse was blown so started lifting components to find the short. Eventually got to two MOSFETs (model FTA14N50C) that are shorted and when i took them out the short was gone.

                Now i didn't have any replacements of the same model of course but i found a couple with pretty similar spec i thought (K10A60D & K12A50D) and put them in. Also replaced the blown fuse with a 3.5A250V one. Checked another time for short circuit and plugged it in....
                04-12-2024, 01:12 AM
              • Loading...
              • No more items.
              Working...