Hey guys, I have a question for everyone regarding my recently built PC:
I put my new PC together and I had all the case fans attached to my PSU and they were all working, so I went to power on the MOBO and the display didn't work, so then I realized I forgot to plug in the 2nd power cable into the MOBO (near the CPU). Once I did this, the PC turned on fine, everything worked so I installed Windows 7, and then powered it down and plugged in the side case fan (with a little 3 prong plugin) into a molex cable I had laying up top, went to power on the PC and it wouldn't boot.
So here I was ,completely stumped, I unplugged the side case fan, switched off the PSU, turned it back on and then the PC booted up. I've had it running for 3 days now (with reboots in between) and my CPU temps are fine (23C idle, 39C load) and my GPU's are also running cool (34C idle, 65C load),
My question is this: should I plug in all the fans into the MOBO? This was my plan after work today, but it just doesn't make sense why it would not power on with that side fan plugged in, is it perhaps because I mis-managed a cable and it's looping back which is causing it not to boot?
System specs are:
HAF 932 Cooler Master Case
212 Cool master CPU fan
i5 2500k sandy bridge
GTX 570 x2 SLI
ASRock P67 Extreme4 Gen3
16GB DDR3 2133 mhz
I have a feeling it's the cable, because everything else has worked fine for 3 days now; I just wanted to see if anybody had an issue like this. I also had that side fan working before in my tests but then later down the road it stopped when I connected it to this one molex cable.
In the future, any time you want to open the case, I would suggest you disconnect the power cord. It is just a general best practice to do so.
When the cord is plugged in, even if the computer is off, there is still power flowing through the cable. That allows the power button to turn the computer on, for instance.
When modifications are made while that power is flowing, strange things can happen that wouldn't otherwise. Components being damaged is one possibility, thankfully it doesn't appear to have happened in your case.
You can already touch the case of either the PC or the PSU to ground yourself. It doesn't have to be connected to the wall for that.
You may have like 1% better grounding if the cord is plugged in, but then you have to remember to turn the power button off every time because if you forget to flip the switch then you can get problems like the OP had.
If you just get used to severing the physical connection you are maximally protected every time.
It is the best practice to sever the connection for a reason.
If the computer is on a carpet or something else that isn't grounded (or if it has rubber feet) it won't ground you by touching the chassis. If it's plugged in, it will completely discharge any static charge you hold.
But if you think you're likely to forget the power switch then it's safer to always unplug it. Damage from static shock is not as serious as it was ten years ago (in my experience anyway) and provided you handle the hardware carefully it shouldn't be too much concern. Plugging hardware in with the power still on is a concern.
Speaking of computer damages...
A guy at my work, today, just burned out a stick of ram by not inserting it all the way before turning the computer on. Don't do that. It makes a funny smell.