Ok, here goes. You will need to follow the instructions in the service manual for the dv4000 for disassembly, it tells you what screws to pull out for what and what to unplug in each stage! If you are faint of heart, get someone else to disassemble for you.
1) Remove the battery, memory cover, hard disk cover
2) Remove switch cover (plastic cover above the keyoboard where the little lights and buttons are) - watch it, its ok to leave it attached to the base while working
3) Remove the keyboard - dont leave it dangling, physically unplug it. To do so, use a small flat screwdriver to pull out the plastic dingy and then just remove the flat cable.
4) Remove the screen (yes, unfortunately it has to go too, so you can get to remove the top cover. It is a lot easier than it looks, follow the instructions carefully, especially when removing the 2 little wifi wires.
You should now have the base with the switch cover dangling.
5) Remove the base case cover (black plastic). Again, follow carefuilly the instructions. If it doesnt click off, do not force it, you've probably forgotten some screen somewhere. Remember the 2 screws in the CD-ROM bay. Remember to unplug the touch pad in the same way you unplugged the keyboard!
6) I'll post the picture of the result when I get home. You now should see the faulty chip as seen in the video of posts above.
I was tempted to remove the metal cover and hammer it as I saw in the video, but resisted temptation - did not make too much sense to do this!
I now cut a piece of rubber the same size as the chip, about 1cm or 1/3 inch thick and placed it on the chip. (will add picture later). I then replaced the cover and tested the rubber height. The plastic cover arched slightly around where the touchpad was, as the rubber forced the cover up (and the faulty chip down).
At this point I plugged everything in carefully and tested the machine for freezes. Everything seemed ok, so I closed the remaining cover screws and reattached the keyboard. Tested once again. Ok - remember if the rubber is too thick the arch the keyboard makes may seem weird, but it ensures the chip will work fine. Remember, we are trying to arch the motherboard down, as we do when pressing above the touchpad to make the crap work.
I reattached the screen and replaced the switch cover.
Final test, perfect.
Ok, I agree that soldering the chip properly or replacing the mother is probably a better and more permanent solution, but I live in Argentina and shipping it to the US or laying my hands on replacement parts was not an option. I admire the guy from Poland who had the guts to send his via mail, if I did that from here I'd be lucky to get the screws back!
One more thing, label the screws and parts carefully, or you'll end up with some screws left over once you are done (I did
If you need any further help, just post here.
Thanks to all you guys posting here over the years, it sure helped to identify the exact location of the problem.