"htc desire hd not turnig on since last charged"に関する回答Change your battery.
"Network wifi lan problem and volume bottons"に関する回答Here, you can try this fix:Fix HTC DesireHD Signal problem
"My phone stuck on HBOOT"に関する回答Weird. Why don't you use a tool instead of trying with the buttons. Check:Easy Ace Rootkit Still seems a malfunction of the board, but you can try. In the worst case you can get a replacement of the board. Saludos.