Question Blinking Cursor Boot Error

[Denz_Carter]

I recently built a PC with this part list https://pcpartpicker.com/list/PH2zrr about 2 weeks ago and had it working perfectly with low temps and running games and applications normally. I first noticed today that one of my games was having an unusually long loading time and a few hours later I had my wireless headset charging through microUSB to USB connected to the back usb on the Mobo. I tugged on the cable which was pinned by my desk against the wall and my monitor displayed greenish lines vertically across the screen with a noisy gradient across the whole screen. The computer shut off and after trying to start it back up, the computer turned on with all fans on and EZ Debug lights normally shifting from CPU to VGA to Boot and then off while the display and keyboard flickered on and off and on again. This continued until the computer entered the blue automatic recovery page and at this point I looked at forum pages and tried various fixes including using the startup repair, unplugging all accessories, unplugging the power and leaving the computer off and entering some commands into the command prompt. These were all successful and I reinstalled windows using a usb with the windows ISO on it that I used when I first made the computer. After the installation, my computer booted into windows but had two vertical blue artifacts on the screen. Shortly after getting onto the desktop and looking at the windows.old file, the computer shut off and went back into the automatic repair loop. At this point I just cleaned my SSD and wiped everything off of it. I also reinstalled the windows ISO on my 32GB usb. Then I tried booting up my computer but started getting a loop of the display cutting on and off as well as the keyboard. The EZ Debug lights continued to go from CPU to VGA to Boot to off and back to CPU in a loop. I tried booting up while pressing <DEL> and the screen would go to black with the blinking white cursor in the top left. I then began unplugging and replugging in the monitor, computer, keyboard as well as swapping around the 2 RAM sticks and booting with only 1 stick. Nothing worked and all I could get was the blinking cursor. I tried taking out the NVME SSD and booting with no usb flashdrive or SSD and the mobo still wouldn't let me open the BIOS pressing <DEL>, F2, F7, F8, F11, or F12 while turning on. There are no beeps during while turning on and after clearing the CMOS by taking out the mobo battery, the computer would start up without turning the display and keyboard on and off, just straight to the blinking cursor without needing to press <DEL>. So with only the mobo, cpu, gpu, and 1 ram stick in I would expect the computer to at least display a splash screen and be able to run bios but it would not. I tried putting the SSD back in and booting with that and it still had the blinking light. I tried booting with only the usb media creation tool plugged in and no SSD and that didn't work. I also tried it with both the SSD and usb but this did not work either. I reseated everything on the mobo except the CPU including the RAM, GPU, 24pin power and cpu power cable, and all case fans and accessories plugged in and took the motherboard out of the case and screwed it back into the case handtight as I had done when I first put it together. Nothing worked and I still got the blinking cursor. The only different thing I could do was when I had booted with only the usb iso inserted. If I pressed F12 while booting up, the screen would go the blinking cursor to the Windows installer page with an artifact on the installer. This could not be done with the SSD and usb both inserted so I could not install Windows onto my SSD. I also tried using different HDMI cables and only plugged the computer and monitor directly into the outlet not a powerstrip. I also tried plugging the keyboard into different usb in case tugging the cable somehow shorted one of the usb ports. None of the usb ports seemed to have physical damage. At this point I can't even boot into the BIOS and am thinking the issue could be in the mobo but I've heard the RAM, CPU and PSU could be suspects as well. Not really sure what else to try and I am considering an RMA on my mobo since I can't even get into the BIOS menu. Is there any other things I could try before doing so? I'm also not even sure if the mobo is the problem I'm having. I don't see how after running perfectly normal for weeks the whole computer wouldn't even start up correctly. Any tips would help thank you.
R7 370 4GB
Arctic Freezer 34 Duo CPU Cooler
MSI B450 Tomahawk Max II ATX AM4 Motherboard
G. Skill Ripjaws V 16GB 2 X 8 GB DDR4-3600 CL16 Memory
Western Digital Blue SN550 1TB M.2-2280 NVME SSD
Phanteks Eclipse P360A
EVGA BG 750 W 80+ Bronze Certified Semi-modular

 

[popatim]

It certainly sounds like the motherboard to me as well. Since you have to take it out to RMA it you could try breadboarding it outside of the case w/minimal components installed.
When you take the motherboard out, examine those rear USB and see if you shorted one of them when you pulled on that headset cable.

Basically connect PSU to the motherbd that has 1 stick of ram, cpu & cooler, & gpu (if you have another gpu to test with as well that would be great) outside of the case.
Reset the bios either by the jumper or taking the battery out for 15 minutes.
Don't connect any USBs but do connect a display.

You should get a Keyboard error when you try to boot it up.
If you get the error then shut it down and add the keyboard. When you boot up it should go straight to the Bios since there is no boot device.

If you made it to the bios, I would update/reinstall the latest bios. https://www.msi.com/Motherboard/support/B450-TOMAHAWK-MAX-II
You'll also need to check out if anything in the case might have been shorting out the bottom of the motherboard. Such as a standoff in the wrong place.

If you didn't get to the bios, then I would call for the RMA.

 

[TerryLaze]

When you take the motherboard out, examine those rear USB and see if you shorted one of them when you pulled on that headset cable.

Probably this, if there is any damage to the USB the RMA could be denied.

 

[Denz_Carter]

Thank you guys I’ll try breadboarding the mobo and see if that works.

 

[Denz_Carter]

I tried breadboarding with only the essentials and it still gives just the blinking white line so I’ll probably look at returning for an RMA

 

[Denz_Carter]

Found out it was the gpu that was faulty. That explains the artifacts on the screen but swapping it for another one worked and everythings working fine now. The motherboard and ssd were both still working fine.