This Apple note http://support.apple.com/kb/HT2341?viewlocale=en_US says:
Some RAM may appear to pass the Power-On-Self-Test (POST) but still cannot be used by the operating system. In this case, the computer will display a gray screen, sound three tones and blink the power LED on the front of the computer three times, pause, and repeat the blinking until the computer is turned off.
Either the Mushkin memory won't work, or 2x4GB won't work in your MacBook. You've probably read that OWC says that MacBook "Unibody" (May 2010) 13.3" 2.4GHz can use 8GB. However, since that's exceeding Apple's spec, it wouldn't be surprising if you need to use higher quality memory, like Crucial or Samsung, or maybe OWC's own branded memory.
Hi BGreg. Thank you for your speedy reply. There are multiple sites that state 8GB as well as Mactracker for my particular model. I went with Mushkin because of the many reviews from other macbook users who had no issue with the particular ram sticks that I bought. I'm not convinced that Samsung or Crucial would provide a different result. Your response has been appreciated though and I'll take your suggestion under consideration if I can't get the full 8GB to work within the next day or so.
Interestingly enough, I just tried using one of the 4GB sticks and leaving the other slot empty. Again the same issue with the beeps and not loading up. I tried the same thing with the other stick and the same thing. It would appear that I need to use one of the sticks that came with my laptop in order to get my macbook to read the 4GB stick at all. This, of course, is not an appropriate solution so I'm going to contact Mushkin to see if they can advise what is going on. If they can't sort it out, I'll take the RAM back to the store and will try either Crucial or Samsung as you suggested.
If anyone knows the deal though, some insight would be much appreciated. Thank you.
Hi David. Would your macbook read all of your RAM modules before cleaning the contacts? Since my macbook will account for each of the modules, just not the two new ones together or the two new ones alone, I feel that is probably not the solution that will work for me.
I'm wondering if it has something to do with the speed of these new modules that I just bought. Even though they say 1066 mHz as do my original modules, is is possible for them to run slightly faster therefore explaining why my macbook will not accept them together or completely on their own (ie. not paired with one of my original modules). I read that if paired with a different speed (not sure my terminology is correct), then the macbook will choose to use the slower speed of the two. So if the new modules are timed slightly fast, this would account for why my macbook rejects them unless they are paired with one of the original (correctly timed) modules.
Well, for what it is worth, I deliberately bought overkill Vengeance 1600mhz modules for my 13" mbp p8700, and discovered something similar, my 4gb module would only work if place in the top slot, with the original 2gb in the bottom one, what wouldnt work was any configuration exclusively with my speedy 4gb modules, or the configuration with 4gb in the bottom and 2gb on the top. It sounds to me like a firmware error, perhaps a deliberate one by Apple, I cannot imagine any engineering reason for this behavior!