Announcement

Collapse
No announcement yet.

Dell Optiplex GX280 no boot and fan going crazy

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    #41
    Re: Dell Optiplex GX280 no boot and fan going crazy

    my gx280 ate a power supply last month, i was using it and it just shut off, trying to turn it back on it would come on a sec then go out. so i just swapped in another untouched psu, the odd thing is that when put to a psu tester it passed, but they don't really put a load on them so probably bad caps.
    My Computer: AMD Ryzen 9 3900X, Asrock X370 Killer SLI/AC, 32GB G.SKILL TRIDENT Z RGB DDR4 3200, 500GB WD Black NVME and 2TB Toshiba HD,Geforce RTX 3080 FOUNDERS Edition, In-Win 303 White, EVGA SuperNova 750 G3, Windows 10 Pro

    Comment


      #42
      Re: Dell Optiplex GX280 no boot and fan going crazy

      I have two of these I am troubleshooting with a run away fan and no boot. One I changed the bad caps with no change so I broke out my meter. What I have found is there apears to be a short in the circuit that the caps and transistors (attached to the big heat sink) are in. If I measure across the caps I get an instant and steady 2 ohms, same with two legs of the transistors. The other board has the same readings. Anyone every see this?

      Searched for schematics online but no luck.

      Comment


        #43
        Re: Dell Optiplex GX280 no boot and fan going crazy

        Forget my previous post. Did not realize one board had a cpu and one did not when I was ohming. Put cpu in the good board and caps read like a short (2 ohms), same as the bad board...

        Comment


          #44
          Re: Dell Optiplex GX280 no boot and fan going crazy

          Originally posted by severach View Post
          GX280 turbo fan syndrome on a normally working system is often caused by the PCIe VGA card pulling out just a bit. Reseat it.
          Reseat the RAM! My Inspiron 530S does stuff like that and traced it to finicky RAM slots!
          ASRock B550 PG Velocita

          Ryzen 9 "Vermeer" 5900X

          16 GB AData XPG Spectrix D41

          Sapphire Nitro+ Radeon RX 6750 XT

          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


            #45
            Re: Dell Optiplex GX280 no boot and fan going crazy

            Originally posted by JayArr_BC View Post
            We've repaired over 50 Dell boards, 270s, 280 and 745s that have what we call "runaway fan"
            I was able to talk to JayArr_BC on the phone last week about reflowing these boards. I have a couple dozen and, at present, my buddy who does my recapping is too busy to try reflowing one of these 280s. I thought I might check here to see if anyone stateside had any experience fixing these.

            Comment


              #46
              Re: Dell Optiplex GX280 no boot and fan going crazy

              Originally posted by Arpajon View Post
              I was able to talk to JayArr_BC on the phone last week about reflowing these boards. I have a couple dozen and, at present, my buddy who does my recapping is too busy to try reflowing one of these 280s. I thought I might check here to see if anyone stateside had any experience fixing these.
              I haven't tried it as I haven't repaired enough of these systems to say... but I wouldn't be surprised if bad BGA for the Northbridge and/or Southbrdige is the cause for the "Turbo fan" syndrome. After all, I know for a fact that the GX270 and other Dells of that era tend to have quite hot-running NBs. In addition to that, the motherboards usually also have a hot regulator or two, typically located near the NB or SB. So again, I'm not surprised if some of them do need a relofw. But keep us posted what you or your friend finds, and particularly what chip needs reflowing. I still see GX270 and 280 systems every once in a while in medical offices and whatnot. These systems are workhorses despite the bad caps.

              Comment


                #47
                Re: Dell Optiplex GX280 no boot and fan going crazy

                I've been through lot of Optiplex and what i can say , they are very sensitive to their Original Cpus and even Fans . Once i was offered one working board because its owner tried to use another type of fans and it wouldn't boot . A very stubborn and sensitive bios they have , and that include Memory sticks if older than two or three years . Resetting memories isn't a perfect solution , just a small turn around for the next trouble . Better replace them with Dell's ones if available .

                And yes , the North and South bridges always get hot .. For my units , not intended for sale , i used to add a small fan as initial precautions at the very first time bought , and therefore extending their life's expectancy . Fact is i preceded Dell in putting heat sinks on south bridge , and maybe if they didn't succeed in going down in microns , we would see fans on the North bridge too . You can say that those fans were also precedent precautions to prevent reflowing issues ..

                Bad caps were also very frequent in those boards especially the big ones ...

                Comment

                Working...
                X