HELP! Can't finish install!

I have a Gigabyte GA-EP45-UD3P that for many years was my main machine.

I'd like to install Sierra on it and use it for doing live streams. I've gotten the machine (after much trial and error) to get to the macOS Installer, and recognize the SATA drive I'm going to install onto. I accept the software agreement and start installing, which the installer tells me will take 15 minutes.

Then, about a minute or so into the install, which seems to be going fine, the system goes to sleep. Or something.

Video cuts out, the fan (usually) comes on, and the USB thumb drive keeps blinking. It will not wake up from this. I let it run all night in this state, hoping that it would be still installing... but when I looked at it about eight hours later, the USB thumb drive was still blinking.

HELP! What is going on here? How can I keep the system from going into this sleep mode?

@slashjpl, please update your profile (personal details) with your build (Motherboard or Model, CPU and Graphics Card).

The Rules said:

Profiles need to contain at least your primary system to assist others with helping you.

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Boot your system in Verbose Mode and post a picture of your screen when it freezes/hangs.
At Clover Boot Screen press space bar and select Verbose (-v)

I'll pull the details a little later today. However, verbose mode won't do any good, as the system hangs after the macOS Installer has booted and we're in the GUI.

slashjpl said:

I'll pull the details a little later today. However, verbose mode won't do any good, as the system hangs after the macOS Installer has booted and we're in the GUI.

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Video cuts out, the fan (usually) comes on, and the USB thumb drive keeps blinking. It will not wake up from this. I let it run all night in this state, hoping that it would be still installing... but when I looked at it about eight hours later, the USB thumb drive was still blinking.

Click to expand...

You are asking questions referring to a problem you have encountered on Video Display during System installation on a hard disk with a Sierra USB Installer Flash disk, but no where can readers of your post see any mention of the "Video Card" used or the "Display monitor connection" used in your post despite Moderator BreBo asking you to update your personal Profile to show not only your Motherboard but your CPU and Video card also.

This is an old Motherboard and I doubt its integrated Video is supported in macOS Sierra 10.12.X .

Please verify whether the MoBo , CPU and Video card are compatible with OS X installation before trying any more troubleshoot with this hardware.

Okay, here's the specs, now that I've able to get back to the computer in
question.

CPU: Intel Quad-Core 2 Q9550 2.83GHz
Mobo: Gigabyte EP45-UD3P
Video Card: SVGA GeForce 9800 GT
Video Connection: DVI

slashjpl said:

Okay, here's the specs, now that I've able to get back to the computer in
question.

CPU: Intel Quad-Core 2 Q9550 2.83GHz
Mobo: Gigabyte EP45-UD3P
Video Card: SVGA GeForce 9800 GT
Video Connection: DVI

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does your processor support SSE 4.1? as Sierra needs that to install

feartech said:

does your processor support SSE 4.1? as Sierra needs that to install

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According to my research, the answer is yes.

I did another install attempt yesterday to try to document the problem on video. Usually, the installer says there's 15 minutes left on the install when it cuts out. This time, it made it all the way to 2 minutes remaining.

Of course, it goes longer than ever and almost complete the install when I try to document. If it helps, I can post an edited version of the video (unless you want to see 20 minutes of handheld footage of a progress bar...)

slashjpl said:

According to my research, the answer is yes.

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have you checked this thread:
https://www.tonymacx86.com/threads/success-ga-ep45-ud3p-yosemite-build.153198/

yes, i know, it is Yosemite.....