Are you sure? I can't seem to transfer the SW3.15 file. Maybe this is my error, but it doesn't seem to work.
Just a tip to anyone not able to get the jailbreak working. (I assume you have the correct files/firmware installed)
When you flip the power switch on the back and start the PS3JB app on your TI-84+ just wait 5 seconds before hitting power.
Tap the power button once and quickly start tapping the eject key.
Here's the part I found useful: DON'T STOP hitting eject (you will keep getting 3 quick beeps) until the PS3JB app says DONE!
I found if I only hit the Eject button once or before it says DONE, the XMB will load up before the jailbreak has worked. I repeat, only stop hitting eject when you see DONE on your TI-84+. You should keep hearing 3 quick beeps if you're doing it correctly
This way works great for me.