Chosen Solution

over heating which causes left side of keyboard to not work. How do I check whether the fans are working?

I use iStat pro to check my fans. SMCfancontrol lets you adjust the speeds manually yourself http://www.islayer.com/apps/istatpro/

I’ve had to replace the fans on three of the 17" machines. All started with the left fan going out first. Failure included a very loud screeching noise at the end. On the first one I just replaced the left fan, then two weeks later the right fan failed. On the next two I torn the machines down to the heat sink, cleaned the vents which were about 70% blocked, replaced the thermal paste on the heat sink. That solved the problems and the machines have not been back in. Here’s how to replace the left fan: MacBook Pro 17" Models A1151 A1212 A1229 and A1261 Left Fan Replacement Here’s the right fan:MacBook Pro 17" Models A1151 A1212 A1229 and A1261 Right Fan Replacement Here’s how to get to the heat sink: MacBook Pro 17" Models A1151 A1212 A1229 and A1261 Heat Sink Replacement Here’s a general guide on how to replace the thermal paste. I use Arctic Silver Thermal Paste: How to Apply Thermal Paste

Your Majesty, Just now saw your note. Thank you. I downloaded SMC control again and found the controls. I have set the temp at 3000 as suggested though the fans are audible they are not distracting. I hope this doesn’t cause earlier wear and tear on the fans. Again thank you and problem solved.