Question Black screen with blinking line in top left (trying to install OS)

Jan 3, 2021
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(If you do not know of a solution, perhaps you could point me in the direction where I could find a solution.)

Yes I am That Guy - new account, asking for your handout, yet giving back nothing as of yet. However, my hope is that your collective generosity and familiarity with troubleshooting will yield a swift solution.

The situation:
I am building my own desktop computer for the very first time, so I am coming in very blind. I even had to buy a keyboard, desk, set up internet infrastructure, and manually learn many things most pc-building afficionados seem to take for granted. The only other computers at my disposal are a 2012 OS X laptop, and an android tablet. That has been one of the biggest obstacles for me, since most people seem to just have multiple brand new computers laying around their mansions so they give me advice assuming I do too.

For months, I researched and collected all the parts, assembled my machine, and now all hardware is on my desk and ready to go. (Unless a component(s) is defective; my biggest fear.) Last thing to do is get the Operating System up and running.

With a bunch of troubleshooting so far on another forum, jumping through weeks of hoops just to get this far, this is where I am:

The OS is on a USB stick (using Boot Camp Assistant), inserted into a USB port. Turn on power. Monitor displays a black screen, with a blinking horizontal line in the upper left corner.

Also yes, I have enabled Legacy in BIOS. And the USB stick is first in boot order. Hardware and cables are seated properly. For reference, here are some links to folks elsewhere who seem to have encountered the same problem:
https://www.techsupportforum.com/th...with-flashing-line-at-top-left-corner.570699/
http://tips4pc.com/computer-problem...-to-a-black-screen-with-a-flashing-cursor.htm

Thank you for taking the time to read!
 
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Yes I am That Guy - new account, asking for your handout, yet giving back nothing as of yet. However, my hope is that your collective generosity and familiarity with troubleshooting will yield a swift solution.

The situation:
I am building my own desktop computer for the very first time, so I am coming in very blind. I even had to buy a keyboard, desk, set up internet infrastructure, and manually learn many things most pc-building afficionados seem to take for granted. The only other computers at my disposal are a 2012 OS X laptop, and an android tablet. That has been one of the biggest obstacles for me, since most people seem to just have multiple brand new computers laying around their mansions so they give me advice assuming I do too.

For months, I researched and collected all the parts, assembled my machine, and now all hardware is on my desk and ready to go. (Unless a component(s) is defective; my biggest fear.) Last thing to do is get the Operating System up and running.

With a bunch of troubleshooting so far on another forum, jumping through weeks of hoops just to get this far, this is where I am:

The OS is on a USB stick, inserted into a USB port. Turn on power. Monitor displays a black screen, with a blinking horizontal line in the upper left corner.

Also yes, I have enabled Legacy in BIOS. And the USB stick is first in boot order. Hardware and cables are seated properly. For reference, here are some links to folks elsewhere who seem to have encountered the same problem:
https://www.techsupportforum.com/th...with-flashing-line-at-top-left-corner.570699/
http://tips4pc.com/computer-problem...-to-a-black-screen-with-a-flashing-cursor.htm

Thank you for taking the time to read!
Whatever it is, it's not bootable. Which OS and how did it end up on USB ?
 

Blackink

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I would try creating another media creation tool for the USB for Windows 7. Sounds like the one you have is no good.

My son has built 3 computers from scratch and the last one had that problem. He's NEVER had a problem like this on a new build so he had a hard time believeing the USB media creation tool was the problem but when he did it again, the install went just fine.
 
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Jan 3, 2021
5
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10
I would try creating another media creation tool for the USB for Windows 7. Sounds like the one you have is no good.

My son has built 3 computers from scratch and the last one had that problem. He's NEVER had a problem like this on a new build so he had a hard time believeing the USB media creation tool was the problem but when he did it again, the install went just fine.
Thank you so much for responding. Today I tried different USB media creation tool, this time using Terminal directly instead of Boot Camp Assistant.

Turn power on, boot into USB, and that yields black screen with white text:

"Reboot and select proper boot device or insert boot media in select boot device"

Which actually already happened to me before arriving at the Blinking Line problem. Do you know what this means? What can I do from here?
 
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Blackink

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Thank you so much for responding. Today I tried different USB media creation tool, this time using Terminal directly.

Turn power on, boot into USB, and that yields black screen with white text:

"Reboot and select proper boot device or insert boot media in select boot device"

Which actually already happened to me before arriving at the Blinking Line problem. Do you know what this means? What can I do from here?
I'm not sure what you mean by using Terminal directly.
Hopefully you're going to the Microsoft Web site to creat the USB tool.

Look up the manual to the motherboard and find out what key you need to press during the restart, to get you into the BIOS and from there you can switch the boot order. It's usually set to boot from the main hard disk upon start up.
Some motherboards can get you right into the area where you can select what gets booted into first without going into the BIOS. Yours may have this feature too.
 
Jan 3, 2021
5
0
10
I'm not sure what you mean by using Terminal directly.
Hopefully you're going to the Microsoft Web site to creat the USB tool.

Look up the manual to the motherboard and find out what key you need to press during the restart, to get you into the BIOS and from there you can switch the boot order. It's usually set to boot from the main hard disk upon start up.
Some motherboards can get you right into the area where you can select what gets booted into first without going into the BIOS. Yours may have this feature too.
Terminal, basically command line on OS X. This OS also has an official USB creation tool, which I used to arrive at the Blinking Line OP problem. To reiterate from OP, I only have an old version of OS X to work with.

I have no problem getting into BIOS.
Also from OP, my USB stick is first in boot order. That brings me to "Reboot and select proper boot device or insert boot media in select boot device", same when I go through BIOS and select my USB stick and boot directly from the USB stick in the BIOS menu.


Try using a windows computer to create you OS disk.
Windows and Mac use a different file system.
Windows can not read a Mac/Apple file system.
Hey thanks for jumping in!

As mentioned in OP, I do not own a Windows computer. But OS X is certainly able to create FAT32 etc, which is readable by Windows machines. Checking the formatting for my current USB stick which Terminal just created, looks like it's:

ISO 9660 (Joliet)
and not FAT32, nor Mac's proprietary junk