My CD player keeps flashing (F15) when I try to play a disc.

It is possible that until you finalize the disc, the only track that will play is the first one. Unfortunately, once you finalize the disc, you cannot record additional tracks to it. You can verify this by finalizing after recording the second track and seeing if they then both play. If that works, you can safely burn additional discs with confidence that they are burning correctly even if you cannot play each back after burning and must wait until finalization to test full burn.

happens to other cd's ?

That can really happen since you will perform cleaning on it,,

You can clean the lens with a small amount of windex and put a little oil like 3 and 1 oil on the spindle motor shaft and on the sled rails. Good luck !

CD Mechanism is possibly faulty. Sometimes won't track the outside of the disc properly. Try other CD's of about the same playing time, if more than 1 disc does it, the fault is usually the mechanism. (If the disc is a lot longer than the standard max CD length 0f 74 minutes, some players may have a problem with them. This was usually with older generation players, so may not be applicable here.)

Make sure the unit is mounted level and not to secured that its pinching down on the unit

MANUAL RECORDING FROM COMPUTER HEADPHONE SOCKET.. FIRST RIGHT LEAD REQUIRED YOU NEED STEREO 3.5mm stero jack plug to lef right phono male leads... prepare for manual record place jack in computer headphone socket. check correct socket play track on computer their should be no sound. if sound present in wrong socket... if ok place phono left right into analogue aux inputs on cdr recorder.next make shure you have blank scratch free cd .next press ext(ernal) source repeatedly until the required input is selected i.e digital analogue optical etc..when auto track is on the disk will number automatically.with auto track on it their needs to be 2.7 second gap to rec number change. with the recorder stopped press rec type five times to enter in the manual record standby mode. manual start s to flash and the display shows REC EXT MAN followed by WAIT.after a few seconds press record . play the source track ie on your computer to set record level on cd recorder.. adjust audio card settings or volume control on pc etc .rotate easy jog/enter key until on the record /play level bar all the blue led are alight but not the red( clipping) display shows xx decibel eg 3bd. stop the source material (track on computer get ready to record ii.e to start track again..to start recording set you track going wilst pressing RECORD on the cd recorder, and immediatley the source material playing. the track number and recording time left appear in display . if check input message is displayed check the connections are correct etc .to stop recording press stop on cd recorder . update lights up and arrow goes out. after recording display will show UPDATE FOR SEVERAL SECONDS WRITTING TOC.. IF YOU WANT TO PLAY THIS DISC ON NORMAL CD PLAYERS YOU NEED TO FINALIZE THE TRACK . HOPE THIS HELPS..yammandan.

Sounds like tracking motor and/or gear problem!
Check for a small crack on the tracking gear.
Parts not avalible from Bose though, they'll only
fix as a "flat rate"!

was it not playing the disc before?

some cd players have a feature that is called intro. it plays typically the first 4 to 10 seconds of a song & goes to the next track. it does this to every song on the cd. see if intro is on your display or if it's turned on in the menu. i hope it works. good luck.