Radio displays "check"

Have you done anything to troubleshoot, such as pulling the radio and checking for power to the appropriate wires? Is this the original radio or is it an aftermarket radio? Have you considered installing an aftermarket radio? You could probably pick up an inexpensive aftermarket radio for less than finding a good original radio if you're comfortable with doing the wiring and installation. But even if you go the aftermarket route you'll want to confirm the correct voltages are getting to the radio and that the grounds are good.

-Rod

check fuses and connectors

Here is a guide that should help you trouble shoot your radio:
http://www.autos.com/auto-repair/repair-a-car-radio-troubleshooting-tips

Troubleshooting the problem may depend on which of several radio options is installed in your vehicle. However, the most probable cause is the antenna. Two different antennas are involved here - one for XM (satellite), one for FM (terrestrial - window type). To start, I would check the FM antenna connections at the window and the radio and the cable between them. If that isn't the problem, the radio is probably faulty.

try check the electricity cable in your car,maybe thats not connected to your radio

What do you mean by "fix" the display, is it not showing it? If so- my Nissan Altima has not been displaying Sirius XM Title and Artist for months. After much searching of the internet, I finally found an answer that worked! Just be sure to write down your radio/sirius presets before you reset the radio - it'll clear them all (and the time). The answer is here- http://incodesystems.com/Troubleshoot/Cars/RadioInitialize.htm

replace the radio it blew the internal amplifier

The radios on older BMWs often have lighting issues where the display is dim or not functioning. To properly fix this, the radio needs to be removed. Open the hinged tabs that cover the bolts and use a small wrench to unbolt the radio. Remove the plastic cover and then pull off the top cover, usually held on with two screws. Remove the display circuit board and then the tape or CD player. This should reveal the main board. Check the bulbs to see if they are getting power. If they are not, they are burnt out. Replacing them is a little complicated but possible for a home mechanic
Read more: Troubleshooting a BMW Radio Display ' eHow.com http://www.ehow.com/way_5437656_troubleshooting-bmw-radio-display.html#ixzz1CNag2wjc

There's no quick solution for this. Have you checked your fuses (specifically the power-bar fuses). Have you removed the radio (audio unit) and checked wiring/connections? If you don't have the wiring diagram, you can go to HMAservice.com's web site and register and access the ETM (electrical Troubleshooting manual) for your Santa Fe (http://www.hmaservice.com/)

I found a solution that sounds reasonable at another site: http://www.automotivehelper.com/topic177704.htm