Any pointers here? I took apart my 2009 i7 iMac (out of warranty) to replace the right hand speaker which was broken. Was easy enough. Speaker now works. However the CPU fan seems to be running 100% continuously form the moment of boot up. My iStat readings list it as running at 0rpm although that's clearly not the case. All other fans are working fine. Temperatures are normal. I know there's issues people have had when adding SSD's but all I've done is take apart and put back together. I didn't even touch the CPU fan. All connectors are back in place including the HD temperature cable. Hardware test gives me the error: 4MOT/4/40000003:HD-1535 which leads me to think that it's something to do with the HD temp. Interestingly if I install Fan Control it tells me the Internal HD temp is zero. Yet iStat reads the temperature correctly at around 29 degrees. So: - looks like all temps are being read correctly. - CPU fan is running 100% yet reading 0rpm - have reset NVRAM/PRAM and SMC etc Any suggestions? Like I said everything is stock and all connectors connected.