Roland. Bosss. Micro BR problems,

Why you have to convert to mp3 ?. Did not the card can be removed and installed on the computer and then copied?
Where you convert the file? BR or computer?
What software you use to convert?

Your best bet is to read the manual. Here is a link to it on Roland's web site MICRO BR Manuals Support Roland

I assume you have tried formatting the card in the BR900... sometimes formatting in the PC's doesn't work. read at this web page:

http://launch.groups.yahoo.com/group/BossBr/message/1905

It’s necessary to bounce all of your tracks to a stereo pair of tracks before you can export your song to a computer as a WAV or MP3 file for burning onto a CD.
1. In normal mode, push EXIT and UTILITY until you see BOUNCE on the display.
Note: The upper right corner of the display shows the track you’re bouncing to. By default, “12V2”—Tracks 1 and 2, Virtual Track 2—is selected.
2. Press STOP and REWIND together to go back to the beginning of the song.
3. Press RECORD, and then press PLAY.
4.When the song’s finished playing, press STOP.
i read some stuff online and this should help.

Sounds like a version compatibility problem.

Check with the folks over at VSPLANET.com where Roland digital recorders are discussed in the forums.

You may have damaged the data on the memory card. If you have no display at all carefully read page 125 of your manual.If it doesn't display with the adapter plugged in try new batteries. If it still doesn't display anything, contact the dealer you bought it from or try contacting Roland. This site should help:http://www.rolandus.com/support/service_centers/

Go to bossbr.net - Plenty of answers there! And yes, you have to master or export the tracks to .mp3 or .wav. These files will be located in the mp3 folder. Boss also makes a free .wav converter located on their website.

First of all, it would be better for you to pan the tracks, and bounce into 2 tracks for stereo separation.

Your "static" may stem from three pausible causes.

One, four tracks into mono may make your output a little muddy.

Two, watch the reverb - if you keep applying reverb after each bounce, it starts to sound bad.

Three, if you have drums/rhythm, turn it off while bouncing. Only have drums on when mastering, because they will keep getting re-recorded during bouncing.

Go to bossbr.net - The best place to get answers!!!!

Ask at www.roland.com/products/en/_support/om.cfm?...
They might be able to assist you.
Good Luck

It is either that you put an incompatible SD card in it. (Believe it or not, many devices will not work with certain SD cards), or the card reader has failed. Try a Scandisk SD card or other popular brand and see if there is any difference in the messages. Otherwise I would say the card reader is faulty.