Power good problem in PSU all voltages seems to be OK

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Zender
    Member
    • Aug 2020
    • 13
    • EU
    #1

    Power good problem in PSU all voltages seems to be OK

    Hi there I just got some Cooler Master mpx-7001-acabw-eu PSU. There is sticker on it so it is not been open ever.

    It have some power good problem, all voltages seems to be ok, but that PG is 0 and blinking on this simple PSU tester, also when on this tester a PSU let out some strange sound inside it ( I can't record it since PSU tester is whistle and covering that sound from PSU ).
    When I try to connect a green and black wire on 24 pin connector a fan on PSU just little move and nothing.

    Here is a video of problem : https://www.youtube.com/watch?v=3cmO8x05lA4


    Question is, like I see voltages are good and only problem is this PG, so does this can be fix easily and PSU will work without problems after that ?
    My skills are only to replace a broken capacitor, and from what I see here that fan try to start and move a little, it like have no enought power to start and that looks like to me, that some of capacitors is out...
    What do you think is this worth a try and if I open it can someone tell me which capacitor to look out since I'm not good to find a problem, only if it is capacitor physically visible that is broken.
    Tags: None
    • stj
      Great Sage 齊天大聖
      • Dec 2009
      • 31285
      • Albion
      #2
      Re: Power good problem in PSU all voltages seems to be OK

      post a pic of the underside of the board,
      there was a psu that was known for this problem that was on russian forums a lot - had a shorted capacitor or diode or something on the underside of the pcb

        Comment

        • Zender
          Member
          • Aug 2020
          • 13
          • EU
          #3
          Re: Power good problem in PSU all voltages seems to be OK

          Ok, I open it up.

          From top side I dont see any kind of problem that I can spot with the eyes, except this big capacitor 400v 470uf that have hump on the center ( it is not flat ).

          And from bottom side only what I can spot is that there can be some problem in marked area.
















          So capacitor is probably out, but if something else can be problem here ?

            Comment

            • stj
              Great Sage 齊天大聖
              • Dec 2009
              • 31285
              • Albion
              #4
              Re: Power good problem in PSU all voltages seems to be OK

              the big cap is probably just the plastic cover sticking up - simple test is to press down on it.
              the arrow in your last pic is flux from resoldering - look above it around the 8pin chip though - that's an interesting area in the photo

                Comment

                • Zender
                  Member
                  • Aug 2020
                  • 13
                  • EU
                  #5
                  Re: Power good problem in PSU all voltages seems to be OK

                  I get a very hard pressure on it and it remain hump on center, it simply can't go down.

                  And I'm pretty sure that I'm firt who open this PSU, so that arrowed problem can be only if something melted there.

                  I desolder a big one since I have doubts about him, and I measure only 1.7 nF on it..

                  I don't know does this device can measure correctly a capacity on this kind of very big capacitor.

                  As picture shows I took one new 25V 1000 uF and do measurements are good, so if this device have ability that can measure this big one, then he is faulty and need replacement ?




                  I also read this on internet : ''PG problem can be due to bad main filter cap, secondary side PWM IC and corresponding components like open resistor, bad caps and leaky diodes. All components related to the PG line can be a suspect.''

                  Where is exactly PG line and what to check more ?

                    Comment

                    • eccerr0r
                      Solder Sloth
                      • Nov 2012
                      • 8709
                      • USA
                      #6
                      Re: Power good problem in PSU all voltages seems to be OK

                      PG = "Power good" line and is exactly what your tester is indicating that isn't transitioning.
                      IIRC it's the gray wire in the standard ATX color scheme.

                      I had a deer psu that failed with power good problems, it turned out a little ceramic capacitor shorted out, causing PG to never rise. Fix was simply to replace the little 0.001uF ceramic capacitor, until deer raised its ugly head again with a different problem...

                        Comment

                        • Zender
                          Member
                          • Aug 2020
                          • 13
                          • EU
                          #7
                          Re: Power good problem in PSU all voltages seems to be OK

                          Ok, so I need to check from other side of board all of capacitors for shorts ?
                          And to replace this big on which is probably dead ?

                            Comment

                            • eccerr0r
                              Solder Sloth
                              • Nov 2012
                              • 8709
                              • USA
                              #8
                              Re: Power good problem in PSU all voltages seems to be OK

                              Well, it's an idea, who knows what's wrong with your particular PSU -- it was what was ailing my deer...

                                Comment

                                • Zender
                                  Member
                                  • Aug 2020
                                  • 13
                                  • EU
                                  #9
                                  Re: Power good problem in PSU all voltages seems to be OK

                                  I will buy this big capacitor 400v 470uf, replace it then I will try. I'm convinced the problem lies there.

                                    Comment

                                    Previous template Next

                                    Related Topics

                                    Collapse
                                    • debidoobs
                                      RX580 all voltages good but won't boot and fan won't spin
                                      by debidoobs
                                      Hi,

                                      Im actually trying to find what is going wrong with my sapphire Pulse RX580 8gb... I purchased it used and supposely dead a year ago and found out (thanks internet) that U1000 (And gate sot23-5) was not giving me the high state to the power management IC NCP8122...

                                      At this time, with no spare parts, i decided to put a 1kohm resistor to create the voltage as commented by a guy named Lorkur on this forum (https://*******/viewtopic.php?f=48&t=122873), you ll need to translate it in english.

                                      and voila ! the gpu worked again and i didn't care much since....
                                      02-11-2024, 02:04 PM
                                    • Capacitorial
                                      Powersupply has all the voltages - Monitor still no power
                                      by Capacitorial
                                      Hello guys,

                                      I have a Philips 240B7QPJEB. The monitor seems completely dead.
                                      I opened it and measured the voltages of the powersupply. I found that a mosfet was dead and replaced it.
                                      On the connector, that goes to the TCON board, all voltages 15-19V and 5V are present.
                                      The small connector on the left of the PSU has two cables with 18V and all the other have 0.2V. It connects on this small connector on the left ontop of the panel. I guess the backlight? Seens fine I guess.
                                      The weird thing is, that the Power LED is powered over the TCON board.
                                      On The TCON...
                                      12-28-2024, 02:12 PM
                                    • Mark R
                                      The Overseas Only Kenwood Model KR 790
                                      by Mark R
                                      I am Repairing this unit. It had many problems. One major one was the power transformer being about 4-5 volts low on the main B+ line which called for 66.5 Vols after the Main Filter caps but only showing about 62 Volts. Caps and the 5 amp Diode bridge were replaced which helped slightly.

                                      The other strange problem was the small secondary winding from the PT which supplies 18 Volts AC to the "FM FLUORESCENT DISPLAY" circuit, and the small winding that supplies 8 Volts AC to the push button grain of wheat lamps. Those voltages were down from 18 Volts to 16 volts. Which was...
                                      09-23-2025, 08:27 PM
                                    • Zeonalbasta
                                      Thinkpad X1 Carbon "LMQ-1MB 12298-2 48.4LY26.021" VCC3M problem
                                      by Zeonalbasta
                                      i have a problem with thinkpad X1 carbon gen 2 "LMQ-1MB 12298-2 48.4LY26.021"
                                      The laptop was turned off because the MOSFET was not transmitting voltage. After checking it turned out that the gate pin on the MOSFET was the problem, because it was producing an inappropriate voltage. and it was discovered that the problem was with the Think engine, so I decided to reprint each pin, and finally the mosfet could work properly. However, there is another problem, even though the voltage has been supplied to the laptop, it still won't turn on, there isn't even an LED indicator. After double...
                                      09-13-2024, 01:17 PM
                                    • netgearnetgear
                                      TOSHIBA 32C100U1 - Faulty display (double images and lines)
                                      by netgearnetgear
                                      Good day all,

                                      I have a Toshiba TV, model 32C100U1 that turns on, displays fine for 5 min, sometimes 10 min and even 25 min then it starts to show double image, wrong colours together with lines as seen in the attached. I have measured and documented the tcon voltages both when the Television works fine and when the problems described occurs. It is important to note that the voltages are the same on the tcon board. The LVDS cable, tge panel ribbon all test good. I resoldred all the main ic's connections pins, connectors and even reflowed gamma chip. I tried to block some of the...
                                      10-27-2025, 08:07 PM
                                    • Loading...
                                    • No more items.
                                    Working...