I bought replacement fan for my Strix 970GTX from Ebay because old fan started to make annoying scratching noise when rpms were high enough. New fan was meant for another model but screw holes, dimensions, amp/volt and wire number&colors+connector were same. So everything should be OK right? Apparently not, because for some reason new fan doesn't spin down at idle like original fans do and it stays at around 950rpm even if MSI afterburner shows fan speed as 0%. 2nd original fan I left in place works like it should. I'm not sure if new fan increases speed either because MSI afterburner shows rpm for both fans combined. Fan rpm curve goes up with temperature but it may be because 2nd old fan still works like it should. To my eye it looks like replacement fan maintains constant 950rpm. What's wrong? Can wires be in wrong order even if colors match?