PAVILION LAPTOP 15-p2495a LID SENSOR

[fastrack-1966]

Have a Pavilion 15 laptop where the light in the power button and the power light (right hand side of laptop edge) both blink when trying to power on, no beeping. This is with power lead only or with battery only. PSU tests fine on a voltmeter and matches the laptop at 19.5V 2.31A= 45W.

Having read other posts I suspect the lid-closing function. i.e. is the laptop "jammed asleep"? Hence does this laptop have a lid sensor or a "Hall effect switch" does anyone know?

[fastrack-1966]

Sorry it is 249sa not 5a!

In fact my query may be over thinking the problem. Does this laptop have a CMOS battery? I've seen the mainboard on its top side, I've no intention of removing it just to find theres no CMOS batt, but the symptoms could be a dead CMOS. Hence  are the CMOS  settings retained by a tiny batt or by the main batt that may be past it's usefulness?

[A_Gayathri]

Hi @fastrack-1966 ,

Welcome to The HP Support Community.  

Thank you for posting your query, I will be glad to help you.

I understand you're dealing with an issue where the laptop powers on but doesn’t boot up properly, as indicated by the blinking power lights. 

Here’s a breakdown of what might be going on with your HP Pavilion 15-p249sa:

Lid Sensor or Hall Effect Switch:

• Many laptops, including some HP models, use a lid sensor or Hall effect switch to detect whether the laptop's lid is open or closed. If this sensor malfunctions, it might cause power issues or prevent the laptop from booting correctly. However, it's less likely that this is the issue if there are no beeps or other error codes.

CMOS Battery:

• Most laptops do have a CMOS battery that helps retain BIOS settings. If the CMOS battery fails, it could cause issues with booting, but it generally wouldn't prevent the laptop from powering on. The symptoms you describe (blinking power lights) are less likely related to the CMOS battery directly.

Possible Causes and Solutions:

• Power Reset: Try performing a hard reset. Disconnect the power adapter and remove the battery (if removable). Press and hold the power button for 15-30 seconds. Then reconnect the power adapter (without the battery) and try to power on the laptop.
• Check for Hardware Issues: Ensure that there are no loose connections or hardware issues, especially with the RAM and storage drives. If you’re comfortable opening the laptop, reseat the RAM and check connections. HP PCs - Testing for hardware failures
• Check for BIOS Issues: Sometimes, issues with the BIOS or firmware can cause power problems. If you can get into the BIOS, check for any abnormal settings or try resetting to default settings.

CMOS Battery:

• The CMOS battery is usually a small coin-cell battery located on the motherboard. On some laptops, it might be soldered or placed in a difficult-to-access spot. While a dead CMOS battery can cause BIOS issues, it’s less likely to be the root cause of the power-light blinking issue.

Refer to this document: HP Pavilion Notebook - 15-p249sa User manual 

I hope this helps. 

Take care and have a good day.

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. 

[fastrack-1966]

Thank you the laptop appears to have "woken up" after leaving PSU unplugged and battery removed overnight. I'm still unclear as to whether this one has a CMOS battery or whether the CMOS relies on the main battery? I really do not want to lift the mainboard to look for a CMOS batt that is not there!

[A_Gayathri]

Hi @fastrack-1966 ,

Thank you for your response, I appreciate your efforts. As the issue persists, I am sorry to hear that I'm sending out a private message to assist you with the next course of action. 

Please check your Private message icon on the upper right corner of your HP Community profile Next, to your profile Name, you should see a little blue envelope, please click on it or simply click on this link.

I hope this helps! Keep me posted for further assistance.

Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos, Thumbs Up" on the bottom right to say “Thanks” for helping!

[fastrack-1966]

Well I lifted the mobo there is indeed a button CMOS battery and it tests fine with a voltmeter. After leaving the AC and the battery out for hours the laptop starts into Win10. However now I'm back to square one with the blinking lights. I don't know if the beeps are "broken" but this laptop has neevr had a beep to accompany the blinks.

[fastrack-1966]

Checked all connections, renewed paste on CPU-heatsink. Fan was very dirty, now clean but could this cause intermittent CPU faults? Order a used mobo from Ebay.incl CPU

[Irfan_06]

Hi @fastrack-1966,

Welcome to the HP Support Community.

Thank you for posting your query. I will be glad to assist you.

I see that there is an issue with the laptop hardware and may need repair.

The support on the HP community is currently available within certain constraints. We are striving to enhance our assistance and broaden its scope. We appreciate your understanding and patience.

I've sent you a private message with the instructions. In order to access your private messages, Click the Private message icon on the upper right corner of your HP Community profile Next, to your profile Name, you should see a little blue envelope, please click on it or simply click on this link

Take care and have a good day.

Irwin6

HP Support

[fastrack-1966 · Accepted solution]

I've sorted it out. After 20+ years in IT I am well familiar with the ATX  PSU and the "Hold the button for 5 seconds as a last resort to power off the computer". However the solution to this laptop power light is a weird one:

Of course I've had the AC and the battery disconnected over & over. Even removed the CMOS batt at one point. However the answer to stop this blinking and bring the laptop back to life was so simple: Hold the power button for 5 seconds. Put everything else back and all is fine.