Chosen Solution

Recently got a broken 16 GB 3G iPhone from a friend. Replaced back cover, screen, ribbon cable for all buttons/headphone jack and Home button module. Works great, but I can only get Wi-Fi in less than half of my house. Older HTC devices (T-Mo Dash and Wing) get signal everywhere in my house, and in front and back yard. Is this normal for iPhone’s, or is there one more piece of the puzzle to repair/replace?

maybe the antenna has a small hairline crack and works only poorly