Hp pavillion dv4 not booting - black screen and blinking LEDs

[MrCatPC]

@ ppaustin11: thanks for reminder to be patient! (:K

...as a repair tech, we often see familiar patterns of error beeps/blinks or messages/symptoms that lead us to obvious troubleshooting sequences. However, your post reminded me to "hurry up & wait."

In the case of my client's dv4 Pavilion, after tuning software & shelving per client's choice to deliver later, upon next boot (before it would leave my shop, thankfully) the dreaded perpetual Caps/Num-Lock blinking began, with no screen illumination, POST single fan spin, and no response. So I did the customary power reset steps, reseated/rotated/removed RAM, checked ventilation, tested HDD externally, did the hokey pokey dance with battery & AC adapter, all with no joy. And I have encountered the BGA chipset failure for onboard graphics & overheated motherboard on this series before, usually paired with high-revving fan & a noticeable burnt circuitboard odor that's fairly tell-tale, but this time was peculiar. The laptop in question was idling cool with low fan speed (not suffocating or overheated as far as I could diagnose without disassebly), just no boot and the LED "morse code" ad infinitum.

I found this thread on Google as top hit for my search, having done all of the above already, and took your advice, fellow honor student, to let it roll. Sometime between 30-45min (I had left a stopwatch running but had other distractions around that time of course), I came back to see a "Resuming Windows" for Vista's boot from hibernation mode, and we happily arrived at a normal user screen. Hallelujah! Right?

Typically this adventure results in a quick diagnosis of "general motherboard failure" for those owners unwilling to pay for disassembly, chip reflow labor, etc., considering moving data to newer equipment is often preferred to resuscitating an older laptop with signs of total hardware failure. I just wanted to say thanks for gently reminding a seasoned technician to be patient because it certainly worked this time.

Now, however, I see that although everything in Windows is acting as it should, the hardware continues to flash its single repetitious blink pattern for Caps Lock & Num Lock, rendering those keys useless for typing, but the keys are ignored by Notepad so that Shift will perform normally and Caps Lock does nothing while typing. I will try a keyboard swap with old parts on-hand, but for now I'm not risking the shutdown process yet. Once more into the (abyss) breach!

Anybody have a definitive answer to this symptom continuing WHILE the laptop is operating otherwise normally? I've been through available HP Support documentation, the LED blink code would indicate a CPU failure if I consider it a "single blink" that loops, rather than "what does infinity mean?" There are approximately 2.5 seconds between single pulses of the Caps & Num Lock LEDs shortly after starting the laptop power and throughout the Windows session now that it's decided to idle in operating system. **Bizarre.**

MrCatPC / Christoph

(it could take 30-45min to read this reply post of mine, so if you've left your laptop blinking this whole time, check your screen & see if it's suddenly alive...)

[edmondclarsr61]

I have a hp pavilion dv4 lap top. It refuses to boot up. Blinking light on the power light, as well as blinking light on the top

and left side of the keyboard railings.

[MrCatPC]

---

@edmondclarsr61 wrote:

I have a hp pavilion dv4 lap top. It refuses to boot up. Blinking light on the power light, as well as blinking light on the top

and left side of the keyboard railings.

---

Hi, edmondclarsr61, and welcome to the forum albeit under less-than-happy circumstances.  My reply was the last one on this thread quite some time ago, so you may prefer to start a new thread specific to your computer's model number, etc., and be more descriptive with details about the issue you're having.  That said, I also assume you're using some other computer/device to read the forum, but if you're on the problem equipment right now viewing this message, please immediately backup your important data before going any further.

If the blinking LEDs you see are power, CapsLock, and NumLock indicators, and there is NO pattern to the blinking, just constant on/off repetition instead of distinct grouped blinking pattern, then you may be experiencing the same hardware failure described above and throughout this thread...

Have you tried leaving the laptop powered on (just allowing it to sit idle and blinking) for 30-45 minutes without seeing any change?  If successful with starting up after giving the laptop a "very long time" to warm up, then I suggest immediately backing up any data you need to preserve and transfer.  The onboard graphics chip or other motherboard components may progressively show these symptoms until the hardware most likely fails completely.  Consult a local (trusted & authorized, locally) technician to diagnose and repair your laptop, but I would advise you migrate to other hardware rather than replacing multiple components or paying expensive labor to fix this issue, without having seen your particular case directly.  If you can get a free or low-cost estimate at a local repair facility, please do.

Disclaimer:

My opinions and recommendations are mine alone, so act accordingly at your own risk, of course.  I happened upon this thread when troubleshooting a client's laptop some months ago, and the temporary solution (call that a "workaround" and not a real resolution) was to let the laptop blink away for half an hour until it decided to finally startup Windows...

Good luck!

~ MrCatPC / Christoph

[Rickul]

Hi,

I just left my problem note which sounds exactly what you have experienced.  Your post was 2011 and it is now 2014 and I have the same problem.  Did you ever get it resolved and if so what was the reason and solution?

This is the same as Mrcat's post (2 or 3 above this)  From timew to time I get it to actually boot but when powered down it will not start again???

[yourpcdoctor]

The problem with those videos is a bad lcd. even that the back lights are good the lcd is bad. Replace lcd .