I'd like to repair a DVD-RW unit of MacBook Pro but ...

My apple MacBook Pro was got a trouble at DVD-RW drive. The DVD-RW unit could not recognize a DVD media. In addition, the unit bring it up after spinning a few times.

I searched a new changeable drive unit from internet shop to change it. I found a shop "eeshop" that sells my searching unit in Hongkong. I ordered the same DVD-RW drive unit GSA-S10N to the shop. It cost $43.99 per unit without shipping cost.

I got it a few days after. I checked the package and article right away.
<-- Left (bought one), Right(original one)
The DVD-RW unit had some scratched marks in bottom face. In addition, it had a label that checked to repair. It was a junk unit not new. But they don't show that fact. That DVD was made at 2007.

Then, I changed it to my MacBook Pro's equipment at a perfect job and powered it on after. But it does not work correctly. A DVD disk was got swallowed in it, but there was no DVD icon on the display.
I tried many times on/off or take any other commands, but there's no instructions on the PC display. The DVD media is in it and I could not reject it from the unit.
Oh my God!