# System won't boot after restart or reboot



## jleonard711 (Aug 12, 2008)

Let me preface by saying that I have built dozens of systems, for myself as well as friends, families, and customers. So I'm no idiot when it comes to building computers, but the problem I'm having on this new system has me completely stumped. I've never seen an issue like it, and I tried Googling the problem and I can't find anyone else who has ever had a similar issue. 

Here's my problem: whenever I try to do a reboot or restart - whether by pushing the reset button on the case or going to the start menu and doing a Restart - it won't boot up. So for example, if I install a Windows update and it tells me I need to restart, it will shut down the system just fine, but then the screen goes blank and it never boots back up. The fans will be on, but it never posts to the boot screen. The system starts just fine when I turn it on with the power button, but it just wont' re-start after hitting the reset button or doing a restart from within Windows. 

I also tried restarting the PC manually by pushing the reset button, and it does the EXACT same thing - the screen will go off, and the hard drive stops, but the fans stay on (although at a much lower speed) and it never restarts. 

I thought maybe it was a problem with the Windows installation, but then I tried it when the computer was in the middle of a bootup before Windows even loaded and it did the same thing. I hit the reset button right when the initial BIOS boot screen comes up, and it does the same thing - the screen goes blank, but all the fans stay on and it never powers down or restarts.

I figured I must have a faulty motherboard, so I got a new one and installed it - but it still does the same thing!

So then I tried unplugging ALL peripherals and accessories from the motherboard(USB connectors, hard drive, DVD Drive, audio, etc), so basically the only things connected to the motherboard are the power supply, RAM, and CPU - and it STILL does the same thing.

So I have narrowed it down to one of the following:
1. Bad RAM. But I'm leaning away from this one, becaues if it was bad RAM then it probably wouldn't boot from a cold start either. 
2. Bad CPU. Again, if it were bad I think it would have problems during any boot up, not just a restart.
3. Bad PSU. Maybe there's something in the PSU that isn't shutting down completely when it tries to restart? 

I suppose I can try swapping the RAM, CPU, and/or PSU to see if I can locate the culprit, but before I did that I thought I'd check in a forum for any advice? Anyone have any ideas what might be preventing it from doing a reboot/restart?


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## jleonard711 (Aug 12, 2008)

Well, I TOUGHT that I had tried everything. The one thing I didn't try was disconnecting the power rails from the DVD drive and Hard Drive (although I had tired restarting with their SATA cables disconnected). Once I disconnected both of those power cables, then it would restart/reboot no problem. So I figured one of the rails in my PSU must be bad, right? So I hooked the DVD Drive back up - still work. Must be the hard drive one. So I hook that back up - STILL WORKS! So apparenlty one of those connectors must have just been loose, and that alone was preventing it from doing a restart or reboot, even though it didn't prevent it from cold-starting or cause any problems during normal operations. Weird.


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