I can help you but much more information is needed. You have the USA 28 but you also have a Translator Pro. So, do you also have another Mac with printer and modem serial ports? That can help find the problem. Please describe your system and connections.
Also, are you using the same mini-DIN8 cables on the USA as when you use or used the Translator? This is important! All 8-pin Mini-DIN cables are NOT the same. Worse, they look exactly the same and have to be checked with an ohmmeter.
When you say "midi led flash it indicate BFL" are you referring to the red MIDI in LED's on the Studio 5? What is BFL?
Again, much more information is needed… we will await your response.