Laptop won't turn on, 5 long blinks,3 short blinks of caps lock button

[Cheryl_Cole]

I opened up my laptop this morning. It had been in overnight. No display. Powered down tried again, no display. Removed battery and all accessories,  reinstalled and tried again. Noticed the caps lock key was flashing intermittently. 5 long blinks,  3 short blinks. Search says system operating board, contact support.

[Lil_Boy_Blue]

Hi

So maybe a BIOS problem rather than the Main Board?

Hopefully one of these documents will cover (and solve) your problem...

https://support.hp.com/ca-en/document/c00042629
https://support.hp.com/us-en/document/c02693833

Turn off the computer, and then connect the power cord.
Press and hold the Windows key and the B key at the same time, and then press and hold the power button for 2 to 3 seconds.
Release the Power button but continue pressing the Windows and B keys. You might hear a series of beeps.
The HP BIOS Update screen displays and the recovery begins automatically. Follow any on-screen prompts to continue the startup to complete the recovery.
HP BIOS Update recovery in progress

If the HP BIOS Update screen does not display, repeat the previous steps but press the Windows key and the V key. If the screen still does not display, your computer might not support the feature or there is a hard drive issue. Continue to the next step to install a BIOS recovery file from the HP website.
If the Power light turns off, the Power button was held too long. Repeat the previous steps, making sure to hold the button for only 2 to 3 seconds.