HP Laptop will not turn on after replacing Thermal Paste and taking off heatsink

[JerryQurn]

Hello there, I have no idea what even happened but when I was cleaning up my laptop and adding new thermal paste and a copper plate, my laptop after putting everything back refuses to turn on, the power led does turn on, but only for a few seconds before turning off and doing that in a loop before shut it off forcefully. When I try putting a charger, no light turns on either.

Any feedback is appreciated. 

[A_Gayathri]

Hi @JerryQurn ,

Welcome to The HP Support Community.  

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

I understand there may be a few potential issues that could cause your laptop to refuse to power on after reapplying the thermal paste and reassembling the heatsink. Here are some steps to troubleshoot the issue:

1. Check Connections

Ensure that all internal connections are secure. During reassembly, it's easy to accidentally leave a cable partially connected or entirely disconnected. Check the following:

• The connection between the heatsink and the motherboard
• Power connector to the motherboard
• Connections for RAM, SSD/HDD, and any other internal components

2. Inspect the CPU and Heatsink Installation

• Thermal Paste: Ensure that the thermal paste is applied evenly and not excessively. Too much thermal paste can cause shorts.
• Heatsink Positioning: Verify that the heatsink is properly seated and secured. An improperly seated heatsink can cause overheating or lack of proper contact with the CPU.

3. Check for Short Circuits

• Copper Plate: If you added a copper plate, ensure it’s not causing any short circuits. It should only be in contact with the thermal paste and the appropriate components, not any exposed circuitry.
• Cleanliness: Ensure there are no leftover thermal paste residues on the motherboard or other components that could cause shorts.

4. Test Without Battery

Try powering on the laptop without the battery, using only the AC adapter. This can help determine if the battery might be causing the issue.

5. Clear CMOS/BIOS

Sometimes resetting the BIOS can help with issues related to power. Here’s how:

• Disconnect the laptop from power and remove the battery.
• Press and hold the power button for about 30 seconds to discharge any remaining power.
• Locate the CMOS battery on the motherboard (it looks like a coin cell battery) and remove it for a few minutes.
• Reinsert the CMOS battery, reconnect the main battery and power, and try to turn on the laptop.

6. Re-seat RAM and Other Components

Sometimes, reseating the RAM and other components can resolve power issues:

• Remove the RAM sticks and clean the contacts with a soft, lint-free cloth.
• Reinsert the RAM sticks firmly into their slots.
• Ensure the SSD/HDD and other components are properly seated.

7. Listen for Beeps or Look for Blink Codes

If the laptop has any diagnostic LEDs or emits beep codes when failing to start, refer to the user manual to interpret these signals. They can provide clues to what is wrong.

8. External Monitor Check

If the laptop appears to turn on (fans spin up, lights come on) but the screen remains blank, try connecting to an external monitor to check if the internal display might be the issue.

Refer to this document: HP Laptop - 15-ef0025wm 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. 

[JerryQurn]

Thanks for the response, but I have made sure and looked. The heatsink is correctly put down, the thermal paste is not too excessive, and the copper plate has stayed only on the thermal paste and area it needs to be. Forgot to mention that before the issue occurred, the laptop booted up when testing the fan before removing the heatsink.

I have no idea where the CMOS battery for my model as I can not find it when opening up the laptop.

[A_Gayathri]

Hi @JerryQurn,

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!