[HD2 Android Q&A, Help & Troubleshooting and Genera] nonpaq:
(Update: over 13 people have reported doing this fix and have seen signal strength improvement. 3 Persons saw no change. 1 person broke the contacts, so be careful!!)

I started a new thread to make this easier to find.

I have found a hardware design defect in the way the HD2 antenna is connected that was the cause of very poor signal strength for my phone. It all has to do with the way the main board connects to the antenna which is part of the back cover. There are no wires, its just a raised "flap" of copper that is supposed to press against the copper pads on the back cover to make the connection when the cover is screwed on. The problem is that there is nothing to keep this "flap" pressing firmly enough against the pad, and in my case a simple drop of the phone had enough force to actually separate the connection just a bit to make the antenna weaker.

Here are portions of my other post from this thread:

Here is the Touch Pro 2 thread I referenced for some background.

If you have weak signal, where every other HD2 works fine, you should do this simple fix. Its very easy and you got nothing to lose. (Note: you will void your warranty since you cant open up the back without removing the screws. Use all the normal protections when handling electronic devices. Remember, do this at your own risk. )

You will need a Torx 6 screwdriver and a flat plastic edge tool to pry apart the casing.(Note: Several people have reported that it is a torx 5 screwdriver. ) As I mentioned, the official HTC training video for disassembly can be found here. You only have to remove the back cover for this so disregard everything after that in the video.

From the tear down photos found here this is what you will see:

Inside the back cover there are three copper "pads" that are the connections to the three antennas: GSM, GPS, and Bluetooth. I dont know which is which, but I suspect the GSM antenna is the largest one (at the bottom). Make sure all three are clean. (Look at this photo, You can actually see dents where the contacts are made.)

Now looking at the main board of the phone, you will see what looks like several raised flaps of copper. These are the "feet" that press against the antenna pads on the back cover.

Make sure they are all raised high enough that they are guaranteed to press firmly against the back cover when closed. Be gentle with them, you do NOT what these to break. They should not be standing straight up, but should be slightly curved. In my case, one of the two at the bottom of the phone was much lower than the other. I used a plastic stick to raise it higher. (After I made my fix, I thought about placing a small piece of foam under the "flaps" to act as a "spring". I may do so next time I open up the phone. Let me know if you do.)

You might get an idea what I'm talking about with this picture:

After this, just reassemble your phone, and you are done!!

I was amazed at the boost in signal after doing this. I think HTC just carried over a poor antenna connection throughout their phone designs, never considering that a jolt could actually separate the connection. Luckily the HD2 is so easy to tear down and get to these connection for an easy fix.