New SSD will not boot internally, only from USB.

No, I am not sure, but it is the first thing I would try

I ordered two cables from china just in case. Can you please report back if you bought a new cable from ifixit. I thought I should try first with the china ones which sell 1 or 2$ a piece unlike the ones from ifixit which sell for 19$.

You don't get much for a buck.

I have also had the same issue mac cloned from OCZ SSD to crucial MX300 SSD boots externally on usb but wont be seen internally my original OXZ SSD runs fine internally and externally only changing for more space, so not convinced a new cable will make any difference at all as I said the previous SSD still works fine, the pattern seems to be all Crucial SSD's has anyone had the same issue with any other brand? I've ordered a Samsung one due monday will see if that does the same,

Change the SATA cable

I agree changing the SATA cable made the difference 😁

ISSUE RESOLVED!! I got a samsung 850 EVO 1tb drive to replace the crucial drive the samsung worked first time as I thought seems a issue with crucial no changing leads and no changing anything else clone done in exact same way using carbon copier won't be buying crucial again!

original fault Crucial drive would only boot externally but not detected once inside mac even tho my original OCZ would,

I read some SSD's not work in macbook with Nvidia SATA chip and I have GoodRam Cx-100 250gb SSD.

I read that in here http://myapple.pl/forums/topic/267894-problem-z-dyskiem-goodram-cx-100-silicon-p ower-s60-na-mbp-20092010/ (translate page with google chrome).

SUCCESS!

So, macbook white 13inch 2007.

SSD wasnt recognized when installed internally. Tried everything, nothing worked.

Ordered three 1$ sata cables from ebay (china). Two of them didnt work and the third finaly worked.

Hurray!

I had the same problem when installing a 250GB Samsung Evo 850 in an early 2011 MacBook Pro running El Capitan. I had the additional problem that I had set and forgotten a firmware password which made it impossible to boot from an external drive.

However, the computer did spontaneously boot from the external drive when that external drive was not the new SSD but the old HDD (connected via SATA to USB adaptor) -- I wasn't asked for a firmware password. This allowed me to clone that original drive to the SSD using Carbon Copy Cloner, something which I had already done but as many other have indicated in this thread, it's cloning from the external old drive to the newly installed SSD that does the trick. It also turned out to be the solution in my case. The cloning happens much more quickly this time around if you had already done it the other way around, by the way, because Carbon Copy Cloner compares the content of the two volumes, so no need to erase the SSD first.

There is nothing wrong with your HDD Sata cable. I repeat, there is NOTHING wrong with your HDD cable. What you need to do is to physically swap the original HDD to be external and the new SSD to be internal. Then boot into recovery mode (command + R) and restore the SSD with the HDD content. The HDD now is external and the SSD now is internal.

However if you feel like buying a new Sata cable, nothing wrong with that.

GunWanderer wrote:

There is nothing wrong with your HDD Sata cable.

How would you know that?

It's like when you're trying to help and you get a negative response like this. You may want to read my post again.

Whatever would I need to do that for, the OP has probably dealt with it after a 3 year interval.

replace the internal cable for the hard disk and it will be work perfectly