MacBook pro three beeps on start up

Phil800w wrote:

Mac book pro three beeps on start up.

3 beeps is a RAM issue.

Try re-seating the RAM: MacBook Pro: How to remove or install memory - Apple Support https://support.apple.com/en-us/HT201165


you are testing for both bad RAM or bad bank—

one stick at a time in each bank, If the RAM sticks prove to work individual—and banks work individually.


Other known issues are: 

worn clips

or

RAM banks slightly distorted/out of flat (use shims)

You can google for more information on these faults and the work a round.

Hi,

As far as I know, three beeps means RAM related issue. Try open bottom case and reseat RAM sticks and see if it solves the issue.

If it doesn't help, you'd need to replace RAM sticks with new one.