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New build won't POST: boot device and VGA LEDs stay dark

I've just finished assembling my first PC. LEDs power on and fans run, but the machine never POSTs and I can't get to BIOS. I'd love your help with this!

Here's my setup:
--ASUS Mini ITX DDR4 LGA 1151 B150I PRO GAMING/WIFI/AURA Motherboard
--EVGA GeForce GTX 1080 FTW GAMING ACX 3.0, 8GB GDDR5X
--Intel BX80677I57600 i5 processor
--Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3000MHz C15 Desktop Memory Kit
--Samsung 850 EVO 500GB 2.5-Inch SATA III Internal SSD
--Thermaltake Core V1 Mini ITX Cube Gaming Computer Case
--Cooler Master GM Series G650M - Compact 650W 80 PLUS Bronze Modular PSU

The motherboard's manual lists four on-board LEDs that, if I'm reading correctly, are supposed to flash briefly in sequence to confirm everything is well. The CPU and DRAM LEDs briefly light up, then go dark in sequence. The other two—labeled BOOT_DEVICE_LED and VGA_LED, never go on. By five seconds or so after startup, none of these LEDs is still illuminated; only the SB_POWER LED remains on.

No signal is available to my monitor through either the DVI or HDMI ports on my motherboard, or through any port on my video card. I've tried a few other things:

--Removed my video card and tried running from just the motherboard ports again
--Removed each stick of RAM and switched their slots
--Powered down, unplugged, and held power button for one minute, as suggested by many on this board
--Unplugged SSD and booted
--Cleared RTC RAM

One other strange thing: The USB stick that I want to boot from in order to install Ubuntu has a light on it. Typically the light doesn't illuminate at all if it's already in the machine when I boot. If I remove it after the machine starts up and plug it back in, the USB stick's light illuminates, but doesn't blink at all in a way that suggests it's being read. The computer fails to reach POST regardless of whether the USB stick is inserted.

I'd be really grateful for any help/suggestions that you all might have. Thanks!
5 answers Last reply Best Answer
More about build post boot device vga leds stay dark
  1. Best answer
    It needs a BIOS update to support a Kaby Lake

    Only thing you can do take it to a shop and ask them to flash it with a CPU the BIOS thats on it supports now

    Or replace it with a B250 / Z270 mobo.

    What CPU is it?
  2. Paul NZ said:
    It needs a BIOS update to support a Kaby Lake

    Only thing you can do take it to a shop and ask them to flash it with a CPU the BIOS thats on it supports now

    Or replace it with a B250 / Z270 mobo.

    What CPU is it?


    It's an i5 7600. I thought Asus had updated their motherboards in this line to support Kaby Lake out of the box, but it looks like I've got just about the only mobo in the line that doesn't support Kaby Lake: https://rog.asus.com/articles/maximus-motherboards/asus-updates-uefi-bios-for-100-series-motherboards-and-intels-7th-generation-series-processors/

    Is there any way at all to flash the motherboard from home, with a laptop?

    (Thanks for your quick reply, btw!)
  3. Nope if it supported flashback you could update the BIOS. But it doesnt support it

    Most B150 or H110 mobos WILL need a BIOS update if you install a Kaby Lake

    Some / maybe not all B250 / Z270 mobos should support Kaby Lake CPU's out of the box.

    Altho, I've seen 2-3 posts in here where people purchased Z270 mobos.

    And the BIOS that was on the mobo, didnt support a Kaby Lake CPU either
  4. Thanks so much for your help with this. I really appreciate it.
  5. No probs :)
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