ATX 300 12E dead

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • rayxoxo
    Member
    • May 2013
    • 34
    • usa

    #1

    ATX 300 12E dead

    Found C36 reading 4.3ohms and slightly bulging. No schematic and just guessing at this time. Replaced c36, but still nothing. Any hints? This PSU came out of an older Gateway.
    Schematic might be helpful.

    TIA
  • CapLeaker
    Leaking Member
    • Dec 2014
    • 8150
    • Canada

    #2
    Re: ATX 300 12E dead

    probably there are more caps bad. Any pictures? Caps still can be bad and look good from the outside.

    Comment

    • everell
      Badcaps Legend
      • Jan 2009
      • 1514
      • USA

      #3
      Re: ATX 300 12E dead

      Measure 5vsb on the purple wire. Should be 5 volts +/- 5%. If not, your power supply will be dead.
      Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

      Comment

      • everell
        Badcaps Legend
        • Jan 2009
        • 1514
        • USA

        #4
        Re: ATX 300 12E dead

        Here is schematic of Bestec 5vsb circuit which should be very similar to yours.
        Attached Files
        Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

        Comment

        • rayxoxo
          Member
          • May 2013
          • 34
          • usa

          #5
          Re: ATX 300 12E dead

          Firstly thank for the schematics - I now have 5v on the purple output lead - No fan or other voltages, no 12s, 3.3, etc.

          Will slowly check out the other caps, etc. Any short cut suggestion appreciated.

          Comment

          • everell
            Badcaps Legend
            • Jan 2009
            • 1514
            • USA

            #6
            Re: ATX 300 12E dead

            Check for shorts on switching transistor and output diodes. Does fan show slight movement when you first turn on the power supply? The other capacitor forming the pi output filter on the 5vsb should also be changed. Bestecs are notorious for having lots of glue which goes conductive and causes resistive paths. Remove as much glue as you can, especially any that has turned brown or black.
            Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)

            Comment

            • rayxoxo
              Member
              • May 2013
              • 34
              • usa

              #7
              Re: ATX 300 12E dead

              Fixed - replaced C36/2200uf 10v. Also fan was stuck - Had an item laying loose preventing the fan blades from turning. How it happened is still a mystery but it must have been the heat originally. Though these are noted for the C36 going south, from the post on this forum.

              Thanks all for the help.

              Ray

              Comment

              • RJARRRPCGP
                Badcaps Legend
                • Jul 2004
                • 6304
                • USA

                #8
                Re: ATX 300 12E dead

                Originally posted by everell
                Bestecs are notorious for having lots of glue which goes conductive and causes resistive paths.
                Looks like the same thing with CWT.
                My 2003 True 430 has the dreaded brown glue.
                ASRock B550 PG Velocita

                Ryzen 9 "Vermeer" 5900X

                32 GB G.Skill RipJaws V F4-3200C16D-32GVR

                Arc A770 16 GB

                eVGA Supernova G3 750W

                Western Digital Black SN850 1TB NVMe SSD

                Alienware AW3423DWF OLED




                "¡Me encanta "Me Encanta o Enlistarlo con Hilary Farr!" -Mí mismo

                "There's nothing more unattractive than a chick smoking a cigarette" -Topcat

                "Today's lesson in pissivity comes in the form of a ziplock baggie full of GPU extension brackets & hardware that for the last ~3 years have been on my bench, always in my way, getting moved around constantly....and yesterday I found myself in need of them....and the bastards are now nowhere to be found! Motherfracker!!" -Topcat

                "did I see a chair fly? I think I did! Time for popcorn!" -ratdude747

                Comment

                Related Topics

                Collapse

                • double_DD
                  How can I be sure that my EC chip is dead?
                  by double_DD
                  Hi all,

                  As the title suggests, how can I be sure that my EC chip is really dead?

                  I've recently gotten into this hobby of laptop repairs, and have successfully brought back to life a couple with some easy fixes, mostly shorted caps.

                  Now I'm working on HP Probook 455 G8, that had some "devil" run around on 3V line, burning a bunch of stuff. Luckily I have a dead 455G7 (for spare parts) so I managed to fix it (swapped burned parts) to a point that it will charge (both on barrel jack and usb-c), but it doesn't want to turn on. There is a 3V3 on a keyboard...
                  03-12-2025, 07:47 AM
                • disorder
                  ps5 edm-033 dead after hdmi/usb ports destroyed
                  by disorder
                  hello guys,

                  i need help to repair a edm-033 ps2
                  history : as always hdmi port and usb ports destroyed after unplugged
                  after change them, ps5 dead too : 1 beep, no blue light. after inspection 1.8v power was shorted, and because of dead panasonic chip. after remove it : no short anymore
                  so i changed it
                  now i have got 5v stby,, 3.3v stby, 3.3v power, 1.8v power and no short on them
                  but the ps5 is dead again : 1 beep, near 10 seconds with power lines and then off, no blue light ...

                  i don't see any projection of liquid metal on pcb.
                  ...
                  01-14-2025, 12:48 PM
                • zunasthegreat
                  Chieftec GPS-450-AA with dead 20N60C3
                  by zunasthegreat
                  Hello everyone hope all doing well!
                  I have this PSU (GPS450-AA delta oem) around for like 4-5 years and I had it recapped early 2020 or 2021 with mostly UCC KY and Nichicon PW's. The bulk was and still is fine, the original Ltec's were bloated and empty. The previous issue was some major coil whine noise and at times random shutdowns when going idle. Today it started tripping the mains breaker and I think I have dead APFC mosfets (20N60C3). Right now upon checking I have the Q1 and Q3 FETs dead so far and I guess those are responsible for the PFC circuit. The only thing I care is If there...
                  09-01-2024, 07:12 PM
                • Beton
                  Finding a dead short component
                  by Beton
                  Hi guys!
                  I searched for the term "dead short" in the forum but no specific thread came up however if I'm just blind and couldn't see the thread talking about this please forward me to that direction.
                  So my problem is I don't know how to find the source of a dead shorted voltage rail. Dead short = ~0 ohm resistance.
                  I have two VGAs (HD 4850 and HD 4870), both dead shorted to ground on the memory rail. I have the boardview file for the 4870 and the memory rail consists around ~7892346 capacitors...
                  I have a bench PSU and if I try to inject voltage the voltage...
                  12-10-2021, 01:05 PM
                • FiguringITout
                  MSI Raider GE75 - Not posting, probable dead CPU
                  by FiguringITout
                  Hello, today I'm working on this lovely MSI Raider GE75 gaming laptop which I bought to flip. Unfortunately, I believe the CPU is toast but I wanted a second opinion before I chucked it into my spare parts bin. I will not have most tools with me today as I'm away from my workbench but I have the basics (a good multimeter, a horrible iron, a solid screwdriver, and my trusty thermal cam). I do not have the original 230w charger, but I have a Dell 180w which was sold with the device and reportedly "worked fine for them".

                  Specs: I7-10750H, RTX 2060, 32GB RAM (unknown manufacturer)...
                  07-25-2024, 07:27 AM
                • Loading...
                • No more items.
                Working...