Power Problem Building New Win10 System w/ ASUS H97i-PLUS Motherboard

I stripped an old chassis and am rebuilding around H97i-PLUSMOB (PSU is Solid Gear FLEX/Mini ITX 320W #SDGR-FLEX320 and CPU is i3-4160).
When MOB & PSU are connected, the MOB Standby Power LEDlights up. However, when 10-1 pin F_PANEL POWER BUTTON pins are shorted together, the MOB does NOT turnON.
Please suggest next steps to troubleshoot. Thanks.
saclarkdoc [EMAIL ADDRESS EDITED OUT]

I have taken the liberty of copying your requests into this reply, and then answering your queries in RED.

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Hello saclarkdoc, welcome to the forums. Could you please list the system specs of the machine. The specs have updated to this machine.

When you attempt to start it, do you get anything at all like fans starting, led lights? Neither the fans nor the lights show any activity.

Are you sure you have the FP Connectors plugged onto the correct pins with the correct polarity? As part of my troubleshooting, I had previously removed ALL of the FP connectors, and have focused on just shorting the POWER SWITCH pins together; again, the result is "no response."

The power button shouldn't make any difference as to polarity. The obvious suggestion would be to make sure all power connectors (24 pin and the 4/8 pin CPU connection)are plugged into the proper connections, and completely seated. I have re-seated them several times during my troubleshooting, but to no avail. However, your suggestion is a good one, and I will re-emphasize my 're-seating efforts.'

Believe it or not, 1/16th of an inch can make a huge difference.

If you have a graphics card installed, check those connections also. I have NO graphics card installed. The MOB has an HDMI output which is adequate for my needs, which will consist of 100% ASCII text and audio files.

Are you running a BIOS version of 2100 or above? Having been unable to get the MOB running thus far, I have been unable to get into the BIOS; therefore, I do not yet know the version.

Failing all of that, I would disconnect the DVD/CD drive, all hard drives and remove any graphics card you may have installed in the machine, use 1 stick of ram, disconnect all FP wires except the power switch and try to start it. This is exactly what I did before posting my thread: I disconnected both the DVD drive and the HDD. I do not have a GPU card. I am using one stick of RAM, and I have disconnected all connectors from the FP connector and am shorting the Power Switch pins manually.

Also, check your manual and see that you have the ram completely seated in the recommended slots. I have my RAM stick in the slot for dual-channel operation. I will try changing it to the other slot which is mapped for single-channel operation.

Do you have a Motherboard speaker installed? Are you getting any beeps from it? I did have one installed, but I removed it as part of my troubleshooting.

Any further info you could give us would be helpful in diagnosing it.

Did you install the standoffs in the correct positions making sure there are no extras and ALL standoffs line up with a motherboard hole with no extra standoffs? Yes, that is correct.

I also notice your Motherboard calls for a +12V 8 pin CPU power connector. Your PSU only has a 4 pin connector. I BELIEVE WE HIT PAYDIRT!! The PSU has both a 4-pin connector and a 6-pin connector (even though the specs do not say so). I have been using the 6-pin connector. I just went back to my workbench and compared the 6-pin and the 4-pin connectors. They are each wired differently: one has the ground connections on the bottom, while the other has the ground connections on the top. When I switched to the 4-pin connector, the MOB powered up for the first time - YEA. Because it is quite late, I will continue troubleshooting tomorrow morning, but it appears we may be OUT OF THE WOODS!! Many thanks for the last suggestion. I'll let you know the status (and whether we can mark this one as "solved") by mid-day tomorrow!

That answers 2 questions for me:

1) You can plug a PCI-E power connector into the 8 pin one on the motherboard, and

2) If you do that, you don't necessarily destroy the motherboard when power is applied

Incidentally, a couple of motherboards I've acquired in recent years have had 8 pin power sockets, but they came with a plug that blocked off half of the socket (to tell you which side of it to plug a 4 pin power connector into, if that's all that the PSU has). I guess that some motherboards don't need the 8 pin power. That may depend on the specific CPU used.

I am up and running great. No damage to MOB!