Blank Display

[Snooks79]

Have HP All In One.  Not used often. On last turn-on, LED light near switch blinks 7 times in succession, but screen remains blank.

[Riddle_Decipher]

@Snooks79 Here's what you need to do, to identify the issue and resolve it accordingly:

• If not done already, check if it works fine on the BIOS screen to identify if it's either a hardware or a software issue:
  • If it works fine on the BIOS (Accessed while tapping F10 during a restart) it's a software issue & I suggest creating a new user account to check if that works better, for starters)
  • However, if it doesn't work within the BIOS either, I'm afraid it's a hardware malfunction.

While you respond to that, I have a few more steps that should help:

Attempt to run a test from the HP hardware diagnostic tool, using this link: Click here for details.

If the display isn't appearing normal on the diagnostics, it could again, determine a hardware failure,

If it works on bios & the hardware tests passed: please update the BIOS, Chipset & Graphics card drivers from the HP website using this link: Click here

if the issue persists, reinstall windows using the recovery partition or the recovery media to fix the issue,
use this link for details on performing the recovery: Click here

FOR DETAILS & FURTHER INSTRUCTIONS, USE THIS LINK: CLICK HERE

(By the end of this article all the issues should be resolved)

P.S: Welcome to HP Community 😉

Let me know how that pans out,

If you feel I was helpful, simply click on Accept as Solution to help the community grow,

That said, I will have someone follow-up on this to ensure you've been helped,

Just in case you don't get back to us within 24 - 48hrs, and have a good day, ahead.

[Snooks79]

The F10 does not work.  Nothing else suggested helps as the screen stays black.

[Riddle_Decipher]

@Snooks79 If it doesn't appear on the BIOS as well, I'm afraid this seems to be a hardware malfunction with the display and I suggest you talk to HP support and discuss your options, follow the below steps to get started:

1) Click on this link - http://www.hp.com/contacthp/

2) Click on Sign-in or select the product using the below step:

3) Enter the serial of your device.

4) Select the country from the drop-down.

5) Click on "Show Options".

Fill the web-form, to populate a case number and phone number for yourself!

Also, if you are having trouble navigating through the above options, it's most likely because the device is out of warranty, if yes? please send me a private message with the region you are contacting us from, 

here's how private messages work: Click here for details.

If you wish to thank me for my efforts, you could click on "Accept as solution" on my post as the solution should help others too.