# Solved: HP Pavilion DV7 won't boot (black screen)



## Darklightr (Oct 19, 2004)

Hi, all,

I was messing around with an HP Pavilion DV7 1243CL (Windows Vista and ATI Radeon card) attempting to do some general clean up and maintenance. I installed AVG Free and ran ATF Cleaner's and CCleaner's clean up tools. I also ran CCleaner's registry cleaner (I know, my mistake). After all this, the laptop was running fine and I shut it down.

Now the computer won't boot. Pressing the power button returns a black screen. The computer's power turns on, all LED lights turn on, and the HDD is powered on. The fan starts spinning about fifteen seconds after power. The Caps Lock LED light blinks once every three seconds continuously. No beep codes or sounds from the laptop.

I've tried to use HDMI to connect the laptop to my TV as an external monitor but no luck.

I've tried running from battery only, from AC only, from battery/AC simultaneously, doing a hard reset, and I've tried removing and resetting the BIOS battery, but nothing works.

Any ideas on a fix? Thanks in advance!


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## flavallee (May 12, 2002)

> I was messing around with an HP Pavilion DV7 1243CL (Windows Vista and ATI Radeon card) attempting to do some general clean up and maintenance. I installed AVG Free and ran ATF Cleaner's and CCleaner's clean up tools. I also ran CCleaner's registry cleaner (I know, my mistake). After all this, the laptop was running fine and I shut it down.
> 
> Now the computer won't boot. Pressing the power button returns a black screen. The computer's power turns on, all LED lights turn on, and the HDD is powered on. The fan starts spinning about fifteen seconds after power. The Caps Lock LED light blinks once every three seconds continuously. No beep codes or sounds from the laptop.


Here is the support and downloads site for the *HP Pavilion DV7-1243CL Entertainment Notebook PC* (NB234UA#ABA) - which came with Windows Vista Home Premium SP1 64-bit installed.

You might want to add and save this site in your browser favorites/bookmarks list so you can readily refer to it when needed.

You didn't say if you have a recovery disc kit for that laptop.

If HP no longer has it available here, Computer Surgeons HP Recovery Center appears to have it available here.

Here is the section on how to do a system recovery for Windows Vista.

Hopefully, the option to do a system recovery from the hard drive is still intact and hasn't been damaged.

If it's not, you'll need the recovery disc kit.

It's my guess you damaged the Windows operating system with your "general cleanup and maintenance".

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## DaveBurnett (Nov 11, 2002)

Any "CLEAN UP" of the registry is not recommended and you must remember that you will only see the damage when you restart. Registry changes are NOT dynamic. You just MIGHT be lucky in that CCleaner does sometimes copy the registry files before changing them. 

If you have a way of getting at the Windows\system32\config folder, look to see if there were any recent back up files.


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## flavallee (May 12, 2002)

> After all this, the laptop was running fine and I shut it down. Now the computer won't boot.





> Any "CLEAN UP" of the registry is not recommended and you must remember that you will only see the damage when you restart


Yep. I learned that the hard way years ago. Changes you make to Windows or the registry seem to go okay - until you restart the computer. 

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## Darklightr (Oct 19, 2004)

Thanks for the suggestions. I researched HP's LED blink codes further and the single flash supposedly indicates CPU failure. It appears that the issue is in fact hardware related and not a consequence of any registry changes. The laptop's owner told me that he's had this issue in the past but after several attempts the laptop would eventually boot.

After numerous attempts at repeatedly powering the laptop on/off without success, I stumbled across this forum thread: http://h30434.www3.hp.com/t5/Other-...-boot-POST-Caps-Lock-and-Num-Lock/td-p/562711

Several people there mentioned being able to successfully boot the computer by opening and closing the optical drive while stuck at the black screen. I tried the same thing several times and eventually had success after putting a music CD in the drive. Once the CD started spinning the computer booted.

Someone in the above-mentioned forum said they believe this problem originates with the laptop's I/O controller. A computer technician posted his solution here: http://www.cybertechhelp.com/forums/showpost.php?p=1235031&postcount=9

Since I got the laptop to boot, I'll be transfering all important files to an external HDD now.


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