The Hall of Shame - Badcaps Photo Montage

Collapse
This is a sticky topic.
X
X
 
  • Time
  • Show
Clear All
new posts
  • mariushm
    Badcaps Legend
    • May 2011
    • 3799

    #561
    Re: The Hall of Shame - Badcaps Photo Montage

    That's a classic transformer, which means the other components are just a bridge rectifier and the capacitor to smooth out the output.

    7.5v and 900 mA makes it a 10-15 VA transformer, and with those low VA values, it's common to have up to 20% variation in output voltage when there's no load.
    The transformer is also selected in such a way as to have higher output AC voltage, to account for losses in the bridge rectifier and to make it possible to use smaller capacitors.

    This, coupled with small voltage drop on diodes at low currents (when you don't have anything connected to it) makes 10v quite reasonable. As soon as you have something connected to it, the voltage will drop.

    As you're dealing with 100-120 Hz, general purpose capacitors would work fine. You're not dealing with 30-150kHz frequencies common with switching power supplies. to require low esr capacitors.

    -

    So basically any general purpose capacitor is fine there. It may have been damaged in factory, but doesn't matter, eventually they die... it's a closed enclosure, no ventilation, and classic transformers heat up when in use.
    Last edited by mariushm; 09-04-2014, 02:24 PM.

    Comment

    • kc8adu
      Super Moderator
      • Nov 2003
      • 8832
      • U.S.A!

      #562
      Re: The Hall of Shame - Badcaps Photo Montage

      panasonic fm issue...again!
      Attached Files

      Comment

      • momaka
        master hoarder
        • May 2008
        • 12170
        • Bulgaria

        #563
        Re: The Hall of Shame - Badcaps Photo Montage

        Originally posted by wacce
        I was aware that it's normal for the output voltage to climb without load, but didn't expect it to go over 10V.
        It is for small transformers like that. And the smaller the transformer gets, the worse the regulation voltage between the loaded and unloaded condition.
        I have a "3V" very small transformer (possibly from a phone or some other old electronics gadged). Unloaded, that thing goes past 9V - three times the stated voltage on the label! Of course, it drops pretty close to 3V with the stated current.

        Originally posted by kc8adu
        panasonic fm issue...again!
        Fake?
        Or are even "invincible" Panasonic caps no longer invincible? I see a bulged C(r)apXon cap in the background.
        Last edited by momaka; 09-05-2014, 09:25 PM.

        Comment

        • ben7
          Capaholic
          • Jan 2011
          • 4059
          • USA

          #564
          Re: The Hall of Shame - Badcaps Photo Montage

          Originally posted by kc8adu
          panasonic fm issue...again!
          I don't see what the issue is :P
          Muh-soggy-knee

          Comment

          • lti
            Badcaps Legend
            • May 2011
            • 2547
            • United States

            #565
            Re: The Hall of Shame - Badcaps Photo Montage

            The sleeve is rotated so the negative marking stripe is pointing at the positive lead. Look at the length of the leads.

            Comment

            • momaka
              master hoarder
              • May 2008
              • 12170
              • Bulgaria

              #566
              Re: The Hall of Shame - Badcaps Photo Montage

              ^ You must have eagle eyes! I would have just installed them and then wondered why they bulged.

              Comment

              • ben7
                Capaholic
                • Jan 2011
                • 4059
                • USA

                #567
                Re: The Hall of Shame - Badcaps Photo Montage

                Originally posted by momaka
                ^ You must have eagle eyes! I would have just installed them and then wondered why they bulged.
                Heh, same, I didn't notice that. However, usually I go by the stripe on the capacitor, not lead length

                I have a new FM (from Mouser,) 3300uF 6.3V
                12.5 x 20 (mm)
                Has the correct lead orientation/lengths too.
                The font on mine looks to be a size or two smaller than the font on yours! wtf?
                The red date-code thing on mine is "3N12QG"
                Muh-soggy-knee

                Comment

                • Heihachi_73
                  Badcaps Veteran
                  • Jun 2012
                  • 713
                  • Australia

                  #568
                  Re: The Hall of Shame - Badcaps Photo Montage

                  I only saw a CapXon issue there.

                  Comment

                  • Pentium4
                    CapXon Be Gone
                    • Sep 2011
                    • 3741
                    • USA

                    #569
                    Re: The Hall of Shame - Badcaps Photo Montage

                    Damn, lti, you're a boss. Nice eye!

                    Here's a new one: MOSTCON. Their name is just them bragging about how they have "THE MOST CON" of any other chinese company It read 159uF. Spotted in a dead Topower 80 Plus PSU. (Check the build quality thread later)


                    Attached Files

                    Comment

                    • wacce
                      Member
                      • Feb 2012
                      • 40
                      • Finland

                      #570
                      Re: The Hall of Shame - Badcaps Photo Montage

                      Originally posted by mariushm
                      As you're dealing with 100-20 Hz, general purpose capacitors would work fine. You're not dealing with 30-150kHz frequencies common with switching power supplies. to require low esr capacitors.

                      -

                      So basically any general purpose capacitor is fine there. It may have been damaged in factory, but doesn't matter, eventually they die... it's a closed enclosure, no ventilation, and classic transformers heat up when in use.
                      That's good to know, thank you for the info. I might change some better quality, but general purpose caps for the warts. And yeah, they are doomed to fail at some point by design.

                      Originally posted by momaka
                      I have a "3V" very small transformer (possibly from a phone or some other old electronics gadged). Unloaded, that thing goes past 9V - three times the stated voltage on the label! Of course, it drops pretty close to 3V with the stated current.
                      Surprising! It's good to be aware of this behavior, as keeping a wart both loaded and unloaded at times will make the output caps adjust to the changed voltage each time, and possibly shorten their life.

                      Comment

                      • kc8adu
                        Super Moderator
                        • Nov 2003
                        • 8832
                        • U.S.A!

                        #571
                        Re: The Hall of Shame - Badcaps Photo Montage

                        at least it doesnt ask permission "can i con?(canicon)
                        Originally posted by Pentium4
                        Damn, lti, you're a boss. Nice eye!

                        Here's a new one: MOSTCON. Their name is just them bragging about how they have "THE MOST CON" of any other chinese company It read 159uF. Spotted in a dead Topower 80 Plus PSU. (Check the build quality thread later)


                        Comment

                        • kc8adu
                          Super Moderator
                          • Nov 2003
                          • 8832
                          • U.S.A!

                          #572
                          Re: The Hall of Shame - Badcaps Photo Montage

                          sometimes a careful examination of what you are working on does more than focusing on the obvious.
                          Originally posted by momaka
                          ^ You must have eagle eyes! I would have just installed them and then wondered why they bulged.

                          Comment

                          • Philly Cheese Steak
                            Senior Member
                            • Mar 2011
                            • 114
                            • USA

                            #573
                            Re: The Hall of Shame - Badcaps Photo Montage

                            Guys need some help(mood feel free to move this, to its own topic under motherboards).
                            I have an EVGA 680 motherboard, no boot no display. I was using a multi meter to check for blown mosfets as the board will do nothing when I hit the button, no sound no noise no power on. The board looks good caps look good, no smell, no nothing
                            So I used a jumper on the green n black wire of the power supply 24 pin harness and boom I got power on, now the 2 (7) segments displays show - - as if part of the board is not getting power.
                            I need a place to start testing and some direction as to what to look for or at?

                            Thanks!
                            Last edited by Philly Cheese Steak; 09-15-2014, 12:26 PM. Reason: spelling correction
                            X99 5930K
                            X99-gaming 9
                            EVGA 1080 Vanilla
                            Gskill 16GBRip JAWS@2400
                            SSD'S
                            Corsair AX1200

                            Comment

                            • kasfamily
                              Badcaps Veteran
                              • Aug 2014
                              • 765
                              • Russia

                              #574
                              Re: The Hall of Shame - Badcaps Photo Montage

                              Radio Koyo KTR-1770 a lot of bad capacitors
                              Attached Files

                              Comment

                              • kasfamily
                                Badcaps Veteran
                                • Aug 2014
                                • 765
                                • Russia

                                #575
                                Re: The Hall of Shame - Badcaps Photo Montage

                                Power supply satellite receiver
                                Attached Files

                                Comment

                                • Heihachi_73
                                  Badcaps Veteran
                                  • Jun 2012
                                  • 713
                                  • Australia

                                  #576
                                  Re: The Hall of Shame - Badcaps Photo Montage

                                  Originally posted by Heihachi_73
                                  I only saw a CapXon issue there.
                                  Quoting myself, it's here too.

                                  Comment

                                  • ReeceyBurger123
                                    Never Give Up !
                                    • May 2014
                                    • 7325
                                    • Britain

                                    #577
                                    Re: The Hall of Shame - Badcaps Photo Montage

                                    Originally posted by kasfamily
                                    Power supply satellite receiver
                                    That cap has gone mental !!!
                                    Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

                                    https://www.facebook.com/Telford-Tel...7894576335359/

                                    Comment

                                    • momaka
                                      master hoarder
                                      • May 2008
                                      • 12170
                                      • Bulgaria

                                      #578
                                      Re: The Hall of Shame - Badcaps Photo Montage

                                      Originally posted by kasfamily
                                      Power supply satellite receiver
                                      Normally I hate CapXon, but in this case I don't think it's the cause of the problem. Look at how charred that PCB is next to it. Something tells me the power supply deisng is shit (either that, or its cooling).

                                      Comment

                                      • ReeceyBurger123
                                        Never Give Up !
                                        • May 2014
                                        • 7325
                                        • Britain

                                        #579
                                        Re: The Hall of Shame - Badcaps Photo Montage

                                        Originally posted by momaka
                                        Normally I hate CapXon, but in this case I don't think it's the cause of the problem. Look at how charred that PCB is next to it. Something tells me the power supply deisng is shit (either that, or its cooling).
                                        Probably due to cooling, most of the power supply's in these receivers aren't up to the job and over work also with poor passive cooling and no fan they burn up easy.
                                        Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !

                                        https://www.facebook.com/Telford-Tel...7894576335359/

                                        Comment

                                        • mariushm
                                          Badcaps Legend
                                          • May 2011
                                          • 3799

                                          #580
                                          Re: The Hall of Shame - Badcaps Photo Montage

                                          No, that mosfet (with heatsink) really cooked the pcb under it. Slim chance it was only poor soldering, but probably the mosfet started to fail internally heating so much it cooked the pcb and the capacitor, transferring heat through leads.

                                          Comment

                                          Related Topics

                                          Collapse

                                          Working...