CQ40-505LA: Black Screen and CMOS issue, laptop not starting (2759 Views)
Reply
Top Student
Carlos2000HP
Posts: 7
Registered: ‎03-19-2010
Message 1 of 3 (2,759 Views)

CQ40-505LA: Black Screen and CMOS issue, laptop not starting

Hi Community,

 

I recently acquired a notebook (4 months) CQ40-505LA and it stopped working. When I “power on” the laptop it only shows a black screen with no information, neither the usual check CMOS messages. The “caps-lock” and “num-lock” led gets blinking. Only once or a couple of times it gave an error message: .. “The CMOS checksum is invalid. The CMOS will reset”

 

This problem started last week when the laptop was running and suddenly stopped working with the black screen mentioned and no error messages displayed.

 

I will really appreciate any suggestion to fix the issue or troubleshoot the problem.

 

An additional question is:  it seems that these new laptops do not have a CMOS battery, that usually where the cause when the CMOS were failing. Is this right? I couldn’t find in the manuals where a CMOS battery could be located for this laptop.

 

Regards,

 

Carlos.

 

For reference of this laptop model , this is the HP link:

http://h10025.www1.hp.com/ewfrf/wc/product?cc=us&dlc=en&product=3966049&lc=en&jumpid=reg_R1002_USEN

Grad Student
compenthusiast
Posts: 266
Registered: ‎02-10-2010
Message 2 of 3 (2,742 Views)

Re: CQ40-505LA: Black Screen and CMOS issue, laptop not starting

Hi Carlos2000HP, I don't know if your laptop has a CMOS battery, but have you researched blink codes?

 

Your pc could be telling you something; read this  document fully.

 

Good luck, and reply back with your progress, please.

______________________________________________________________________________
ProBook 4710S, Win 8 Pro 32 bit, T6570 @ 2.1Ghz, 320GB, 3GB, ATI Mobility HD 4330
Elitebook 8440p Win 7 Enterprise x64, M520 2.4 Ghz, 250GB 4 GB, Intel HD Graphics
Top Student
Carlos2000HP
Posts: 7
Registered: ‎03-19-2010
Message 3 of 3 (2,710 Views)

Re: CQ40-505LA: Black Screen and CMOS issue, laptop not starting

Hi compenthusiast,

 

Thanks for taking the time to answer, I followed the advice but I have not succeeded, I checked for the blink codes, but the laptop keeps blinking the “caps-lock/num-lock” led continuously with no stops, so I cannot match the blink with any code in table (they go from 1 to 6 blinking in the table for the caps-lock/num-lock). The only noise I can hear for a while is the fan cooler and stops a fewer seconds after I power on the laptop.

 

The other option I tried was to do a “bios hard reset” by taking the battery out, disconnecting the AC Power and pushing down the power button for 20 seconds as indicated in the troubleshooting.

 

Also y took out the RAM memory module and inserted again just to check In any case thanks for the advice!, If you think there could be other options to try, please let me know and see how to get the BIOS back.

 

Regards, Carlos.

† The opinions expressed above are the personal opinions of the authors, not of HP. By using this site, you accept the Terms of Use and Rules of Participation