Charging light blinking 8 times and not charging in HP ProBook 4540s

[Mohamed_Nathoo]

Hello, 

4 months back, i had purchased an HP ProBook 4540s which worked perfectly but has showed me problems when i need it the most, i had left the laptop switch on for like 2 hours and when i get back to it, it has switched off. I switched it on and it worked perfectly except that it wouldn't charge. When ever i connected the Charger, The charging white light blinked 8 times and didnt charge, i tried removing the battery and switching it on while plugged in but it doesn's switch on, the white light blinks 8 times again. I guess the battery doesnt have any problems since i did the battery check in HP Support Assistant. I have tried the following methods: 

"Disconnect AC, Shutdown, Remove battery
Connect AC
Startup (w/o battery)
Open Device Manager
Expand Batteries category & right-click all of the "Microsoft ACPI Compliant Control Method Battery" listings (ok if only 1)
Select Uninstall
Click OK to confirm
Expand System Devices.
Right-click the “ACPI Fixed Features Button" and select Uninstall.
Click OK to confirm
Shutdown, Disconnect AC, Insert battery
Connect AC
Restart the machine"

But i get stuck in step 3 because the laptop doesnt startup without the battery, i've also tried the following

"1-turn off the notebook

2-remove the battery

3-remove the charging adapter

4-Now press and hold the power button for 40 seconds(it will discharge the capacitors)

5-now insert the charging adapter only(dont insert the battery)

6-now press the power button

7-let the windows load and then shutdown it

8-now insert the battery and press the power button"

None of these solutions work, I woud kindly like someone to assist me really fast as i have a school project pending.

By the way my HP ProBook 4540s is running Windows 8.1

[hs007]

From hard resets to taking the battery out to holding the power button down then taking the battery out....lots of combos were tried.  After exhausting all options, I decided to unplug the A/C and let the battery drain out.  Because the fans are still running it will eventually drain the battery.  After I drained the battery, plugged back in the A/C after 5 minutes of letting it semi-charge, I turned it back on and Euerka!

This should work..I thought I was doomed!  So just let your battery drain while it is on even though the screen is blank. Remove the A/C obviously to drain the battery.  Once the battery is drained, this will automatically shut off your laptop.    Once you have drained the battery, plug it back in - after a few minutes of it chargning, turn the laptop back on and it should work!

[hs007]

I have also had the problem where my A/C is plugged in, but the LED display light is red as opposed to white which would show that the laptop is charging.  The computer thinks that there is nothing plugged in, while there is.  It still charges, but the laptop does not recognize as it charging.  So even though you may not think its charging, it still may be.  Leave it plugged in.  Other than that, it is some sort of Windows update glitch, that Microsoft fails to acknowledge from what I have read. 

[Mohamed_Nathoo]

Ok thnx, ill definately try your solutions and let you know what worked. My battery is already drained out, now i just need to try charging it.

[Mohamed_Nathoo]

Battery has already drained, its been charging for over 10 minutes now, still not turning on

[Mohamed_Nathoo]

Hello again guys, 

I have figured out that the problem is not with the laptop or the battery. The problem is the charger itself. I tried using my friends charger and it worked perfectly. I guess my adapter has just blown off.

[AftabBD]

May be check this out (http://h30434.www3.hp.com/t5/Notebook-Lockups-Freezes-Hangs/HP-Pro-book-4540s-power-jack-is-flashing... was a simple fix for me, idk about 8 blinks but mine was continuous ... this usually happens for the distortion/bending of the thin charging wire on the cable. ..