New computer won't boot anything

[Aisling]

Just the price difference really. :P But that's not much, in the end.

[Der Cute]

Corsair has a great reputation, so does Antec, Coolermaster.
I've always used Antec, just because I had an Antec case. It just fit right. As Chromatics said, disconnect everything, including the vid card.
I would have this plugged in: CPU. 1 of the ram sticks (closest to the chip). Mouse. Keyboard. Hard drive. If you have onboard video, please use that (blue female plug on back end of motherboard, also in manual).
Just the very bare bones. Oh, for shits and giggles, disconnect the fan(s). You're only doing a short quicky boot here.
Fire her up. LISTEN. Do you hear the hard drive spinning up? Ok. Any beeps? (hope you get a code beep please god). Ok. If you have the basic video, good. Can you get to the Bios?
(as soon as you fire the puter up start smashing F2 or F11).
If you get to the BIOS, it's blue background with white text, fugly bare bones stuff. Let us know.

The reasoning here is to figure out if any of the RAM sticks are bork, if the vid card is bork or pulls too much juice, and if the fans all start up too quick making it impossible for the PSU to feed everyone at boot.
So again: CPU. 1 RAM stick, the closest to the CPU (remove other pls). Basic low level video if you can. Keyboard, mouse, ONE drive. Nothing else. Listen closely, you need to see if the drive spins, and if it sounds good.

After this step, let us know, we can go further with this.

[Aisling]

We tried a bare-bones. Results varied. Sometimes it worked, sometimes it didn't. We did sometimes get into BIOS, yes. Sometimes we didn't. Sometimes the drive started. Sometimes it didn't. Sometimes the power cut out partway through starting things up.

Anyway, we've already pulled out the power supply and boxed it up for returning. We're 99% sure it's that, since none of the other troubleshooting changed the results permanently. But thank you for your help. If the new better power supply doesn't fix things, I'm sure I'll be back, tail between my legs.

[dalesys]

I'm still a little suspicious of the motherboard mounting divots. I'd try unmounting the motherboard and laying the whole megillah out on a tabletop.

[Aisling]

If the divots are the problem, though, what do we do about it? Some kind of washers or something?

[dalesys]

Either standoffs positioned matching the mounting holes of your motherboard or insulation covering the divots that don't match the mounting holes of your motherboard. Perhaps little plastic buttons like are used to cover furniture assembly holes? Electrical tape would work for testing, but I'd worry about it wearing through from vibration over the life of the unit. 2-4 thicknesses of 3x5 card stock glued together and secured over the extra divots?

The case you specify can take an ATX or a microATX motherboard, both of which have (9) mounting holes, only (6) of which are common to both, so there would be (12) divots/mount points.

Another question I see is how big the divot tops are? Is the size essentially the same size as the common standoff? If it is bigger, it could be touching other circuit traces on the motherboard.

[Aisling]

I don't think there's any other holes that line up on the case and motherboard. There aren't any divots that don't have screws in them right now... What kind of insulation would you use?

I'll doublecheck if we can move the screws tomorrow. It's way too late to pull it apart tonight.

The divots aren't very big. I don't think the part touching the motherboard is any bigger than a washer would be.

ETA: we just took a peek, because of course sweetie couldn't leave it for morning. It doesn't look like the divots touch outside the ring around the holes in the motherboard. We can put some kind of washer on anyway, if people think that would help? It'd be great if someone actually replied to that idea, please.

[dalesys]

This is a hole layout I found that should be correct (wafts incense towards the God Murphy):

Holes A, G & K are ATX only (and outside a microATX).
Holes B, R & S are microATX only (and under aN ATX)
Holes C, F, H, J, L & M are common to both.

Insulation? tough paper/plastic 1/32-1/16" thick covering the three microATX divots, probably glued to the case with a dab of silicone rubber glue.

[Aisling]

There are some holes with divots, and some without. But the only holes that match up to our motherboard are the ones with divots. So not using them isn't an option, unless we get a whole different case.

[sms001]

Thanks dalesys. I keep leaning toward mb short myself, just because of the sometimes full boot/sometimes nada. Another thought is a farked mb - either a lemon, or a temp critical solder/trace line somewhere.

Keep us posted Aisling. Got fingers crossed for ya'.

[Aisling]

I really hope it's not the motherboard. But I won't know until the new PSU gets here and we install it. Hopefully that'll be some time next week.

[dalesys]

Which is why I suggest removing everything from the case and hooking it up on a tabletop (not metal).

That would elimnate the possibility of a mounting intermittent short, though I agree that power supply or motherboard faults are likelier.

[Aisling]

If it's the motherboard, we'll have to take it to the shop anyway, because we can't get the CPU fan off again. :/ This computer, I swear... so much more trouble than the last one we built.

[Chromatix]

I really don't think it's the mounting. That wouldn't cause an intermittent fault, instead it would cause it to not work at all (and possibly let out the magic smoke). A good case - and Thermaltake should be good enough - will make sure that if you can get the screws in, no short-circuit is possible.

Leave everything else alone for the moment and just try the new PSU. If it still behaves the same way with the new PSU, we can be more aggressive with the troubleshooting.

[emax4]

Another possible problem with intermittent power may be the power button itself. I had a Rosewill case where the buttons were snapped in to the front of the case itself, and the wires from the buttons were coming from the switches (buttons) through a hole in the chassis and routed to the motherboard. Over time of opening the front panel of the case and pulling it off far enough to work, the ground and positive wires from the switch came loose. My newer Antec 300 case has the power and reset switches attached to the chassis itself, so I can take off the front panel as often as I want to without needing to worry about the wires coming loose from the switches.