Completely Blank Screen on Start Up

[YHS]

I have an Envy laptop with a Windows 10 OS.  Recently it only displays a blank screen on start up, and nothing else.  

I have looked through the forum and the solutions suggested for similar problems did not work for me.  The only useful indication is that my caps lock LED light blinks 4 times, then pause, and keeps repeating this pattern after I tried to get into the BIOS recovery screen.  However the screen remains blank all these while, with the fan noise going on louder than usual, and I could not get into the BIOS recovery screen.

I would greatly appreciate any assistance on this.  Thank you! 

[mdklassen · Accepted solution]

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@YHS wrote:

I have an Envy laptop with a Windows 10 OS.  

Recently it only displays a blank screen on start up, and nothing else.  

The only useful indication is that my caps lock LED light blinks 4 times, then pause, and keeps repeating this pattern after I tried to get into the BIOS recovery screen.  

The screen remains blank all these while, with the fan noise going on louder than usual

I could not get into the BIOS recovery screen.

How old is the computer? Is the HP Warranty still active? If so, contact HP to get it repaired/replaced, at no cost to you. If the warranty has expired, HP will repair it, but not for free.

Your symptoms match a total failure of the motherboard.

Because it does not successfully complete the POST (Power On Self Test), the fans stay spinning at 100% speed, and 100% noise.

See:  HP and Compaq Desktop PCs - BIOS Beep Codes

for an identification of the specific "beep" (or flashing LED) codes.