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Computer shut down, no reason, no fans spin, new PSU and mobo

  1. So I was watching a video from my 'Nix box last week while running some pretty heavy CPU intensive apps and the computer froze on me twice, My CPU never freezes so I thought that it was odd but the PSU and GPU were running a little hot so I thought I would tone down the usage as I had just installed some new cooling fans a day before and a new CPU about a month earlier. Then the computer shut down and wouldn't start back up. I replaced the PSU originally thinking that since it had been running hot maybe it just died. Installed and no power no fans nothing. Replaced the mobo with the same results, I'm at a loss right now as to what the problem could be. I even switched out the push button in case that burned out somehow and nothing. Any ideas where to go from here?

    Update: just an update after posting I found the POST walkthrough and followed it step by step and still nothing. Would a bad CPU cause there to be no power through the whole board? I replaced the CPU fan as well to be sure and I can't seem to find any other possibility.
  2. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,813   +159

    Yes a bad CPU would cause the board not to function, but bad CPU's are very rare unless they are damaged by handling or installing. What type of CPU is it? The socket type can matter for damage
  3. avengingwatcher

    avengingwatcher TS Rookie Topic Starter

    actually swapped out the CPU and that wasn't it. I'm fairly certain the brand new PSU was DOA even though the light came one. I've got a 300W PSU that runs the fans but not enough juice to spin up the disks. Just received some new PCs for free, might see if I can get one of those to work on it.Thanks for the reply!
  4. terry5880

    terry5880 TS Enthusiast Posts: 527

    the power plugs from psu or power on button are they connected to the right terminals as i found on 1 of mine they was connected wrong when i swapped them . bingo
  5. robin_bga

    robin_bga TS Rookie Posts: 258

    Hello,
    Am actually thinking that you didn't peal off the little paper that sits under the Heatsink, so that could be you problem, if not then there is no good contact between the CPU and HEATSINK...
    Hope that helps
  6. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,813   +159

    A lot of people forget to connect the AUX 12 volt 4-pin connector to the motherboard near the CPU. The only front panel wires that have a polarity position are the Power and Hard Drive LED connections
  7. treetops

    treetops TS Evangelist Posts: 1,666   +57

    Yeah you really have to pay attention to your psu requirements.
  8. avengingwatcher

    avengingwatcher TS Rookie Topic Starter

    Wow thanks for all the response.

    Terry, I just double checked the pinout and there is no way it would have fit if it was improperly set in.

    robin-bga, There was no sticker on the bottom of the heat sink, I was pretty meticulous about that process as heat dissipation was a concern of mine. Computer under load was running about 32C, but the GPU was running a bit hot, so I brought in a quiet 120mm intake and upgraded my outtake fan to be quieter and push more air. Also cables were zip tied and tucked out of the airflow.

    T-magic, that cable was definitely installed. I made that mistake once when I first started building computers years ago.

    treetops, Agreed but the new PSU was actually a bigger one. I moved from a 500W to a 550W PSU and the new one came with dual fans.


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