Answer to: No wifi bloutouth no signal?Your iPhone's wireless chip needs a reflow (reheating) , use a heat gun that should get it working. vids on youtube.
Answer to: Powered up, stuck with apple on screen?start up your mac holding the comand(apple key),option + P + R your mac will reboot, keep holding those (4) keys down till the 3rd chime and release. If not insert your Mac Os X installation DVD and reinstall the OS
Answer to: Stuck on startup after software update.Load the restore installation disc that came with your mac in your mac, reboot while holding down the option(ALT) key. restore your system.