I have opened imac g4 case in order to replace original 92mm fan. For replacement I found exact size ZALMAN ZM-F2(3 pins). But when i reached fan connector found that yellow wire is not connected only red and black one powered. As i guess the yellow one should be used to control fan speed but where to get power for it ? The G4 i own is second hand and fan connecter was soldered so seems that is not original connection.
