This post is meant to highlight a design and manufacturing error in the base and top cover which I'm sure HP is well aware of. There are 5 mounting screws that have brass nuts which are set into plastic on the top cover (not the screen, but the palm rest surface) to keep them in place. 4 are for the lid & arm, and the other is for the base cover which keeps the unit from separating when opening the lid. This problem appears to be caused by long exposure to heat from the CPU fan and heatsink. Over time the plastic hardens becoming brittle and physical damage (like a drop or hard setting on a table) cracks the plastic.
In my experience, this could have been a much bigger problem if I had not taken quick action and disassembled the laptop to try and resolve the issue. In short, the pieces of plastic became scattered around the board and one ended up in the exhaust fan. I didn't allow this to continue very long, but it's not a stretch to see that it could have jammed up the fan causing a potentially catastrophic failure. You could hear the fan banging around the plastic when tilting the laptop.
|In this photo, all of the plastic screw assemblies have cracked from heat. |
In my search to resolve this I ended up on HPs PartSurfer catalog and went through each part number trying to see if the plastic mount itself was available for purchase. Unfortunately it is not, and is part of the "Other PCA Assems" category. The part is called "SPS-TOP COVER CURVE" which is the entire palm rest cover. The part number is 720271-001 and is priced over $100 from HP. I decided to check eBay and prices were similar there. Of course, there were some used pieces and they were marked as "for parts or not working" - what was wrong with them? Of course, busted plastic screw mounts.
I was able to fish out all the broken pieces and reassemble the laptop and took a few pictures to visualize the issue. A word of advice: you do need to unplug the CMOS battery to disassemble the laptop so check your BIOS settings if (customized) applicable and record them.
I'm no engineer, but my suggestion would be to create a wall with a thin metal shielding around the plastic screw area to prevent heat from getting in there, and also make sure that it is complete from the base to the top so that if plastic does break off, it cannot be scattered around the chassis.