(sorry for my english. Its not my primary language)

I have a MacBook Pro mid 2011. I've installed a SSD on the main bay, removed the optical drive and installed a caddy with the a regular HDD on it. The OS was installed on the SSD. This setup works fine!

Last week I had to force a shut down by pressing and holding the power button. After that, my system didn't boot. (a question mark apperars)

I install El Capitan again on my HDD and right now I'm trying to format/erase/restart my SSD.

If I change hard drives places (putting SSD com the caddy and HD on main bay) it works.. I can erase de SSD, reformat, etc, using Disk Utility.

But with the HDD on caddy and the SSD on the main bay, my mac dont recognize my SDD and I can't erase, or format it.

My goal here is to reinstall El Capitan on SSD using it on the main bay because its faster and have a better performance.

Does anybody have a ideia about it?