MacBook Pro start up error..

Question

when I turn on my Mac a black screen with an Apple icon in the middle appears, it seems to be an update and right afterwards it will shut down.
I can turn the Mac back on but it will go back to the same loading screen as before.
we used another computer to run diagnostics on the Mac to see the issue and later found it was either the heat sensor or the hard drive is fried.
the only time I had this problem is when I updated to osx 10.9 mavericks.
my question is how much would the repair be if the hard drive and or the heat sensor fried out.
It is also around four years old if that may be can a contributing factor to this problem.
I feel the update is here to blame since it has slown down my device.
I've never experienced this with my Mac before.
I'm a huge Apple supporter, I've had almost every Apple product created.
please tell me there's a way to fix this.

Answer 1

Thomas1550,
if this is due to a problem with your MacBook Pro’s internal hard drive, then you could buy a new 2.5-inch SATA hard drive or SSD (and a T6 Torx screwdriver if you don’t already have one) and replace it yourself, if you’re comfortable with simple DIY computer repairs.
If it’s due to a problem with the thermal sensor, then you could try replacing your MacBook Pro’s heat sink, which includes the thermal sensor; it’s not a particularly expensive part, but the replacement process is time-consuming. If replacing the heat sink doesn’t solve the problem, then your logic board would probably need to be replaced — and a logic board is quite expensive.
If you’re not comfortable with DIY computer repairs, you could take your MacBook Pro to an Apple Store (or other computer repairer) and get a price quote.