Is it safe to install my motherboard with only 8 out of 9 standoffs? If so, is there an ideal arrangement?

Question

I bought a case and it came with only 8 standoffs. My motherboard has 9 spots. Is it relatively safe to install my motherboard anyways?

Answer 1

I'd sure like to see a pic or dwg layout of the PCB, but that's ok.
The standoffs of course are basically to hold the board flat after it's been installed.

I would certainly be sure you have one on each corner, one in the middle and then on the long sides you can pick one to leave out that won't allow the board to raise up or tweak.

What could possibly happen if the board tweaks is in time one or more of the surface-mount components (SMD) could end up with fractured solder joints or even lifted joints or even worse, pads. This is the worse case scenario however and probably won't be something to worry about depending if you are sure the board stays flat enough.

Just keep in mind though that the engineer who designed the board put nine standoffs for a reason.
Could you backorder the missing standoff and install it later?

Answer 2

Yes, the motherboard will still be OK.

BUT inspect your motherboard first. Look for portions where there are NO slots that you need to plug in something and unplug later. An example would be the upper left corner. You can leave that mounting hole without a standoff.