Sony lbt d209cd cassette decks won't open to eject tapes

You may have an issue with the cassette deck on your Sony LBT-D550. The cassette deck uses a belt drive system to operate the cassette mechanism; if belts are broken, it can cause the deck to malfunction.
All the belts may have failed at the same time, but it's also possible that there is another issue causing the problem. Some possible causes of a cassette deck malfunction include:

• A problem with the cassette mechanism itself, such as a jammed cassette or worn-out gears.
• A problem with the cassette deck's motor, which a malfunctioning capacitor or other components could cause.
• A problem with the cassette deck's control board, which a malfunctioning switch or other components could cause.

To determine the cause of the problem, a professional technician should look at the cassette deck.

bit late...but. STOP ASAP! by removing the battery, after removing battery, wait 20 seconds, re-fit battery & CLOSE the cassette door.
then wait 10 seconds, slap the closed door twice quite firmly. then open, if it opens, discard that cassette tape, clean the players head using cleaning tape.
use new cassette tape.

Is a cassette stuck inside??

Prying the door open is not the first thing that should have been done. The mechanism for the tape transport is having a problem in that it either need service or the belt is too loose. A Technician would open the deck get the mechanism in the stop mode and then eject the tape. Any other way just damages the unit and might make it unrepairable.

If you remove the cover after unplugging the AC, you will see that when you push the eject button that on the back side the putton is held back by a white plastic piece. Push down the white plastic piece as you press the eject button. The door will open and the tape will release. I jsut did this today on my Sony TC WR 670 dual tape player. Both sides were blocked. I noticed that both fuses on the board were also blown. New fuses didn't solve the problem. May be that the transformer is out?

Is the tape wrapped around the capstan?

I had the same problem. You probably have to replace the rubber belts.

the motor that drives the mechanism is jammed or burnt out.if you remove the cover and turn the big metal weights driven by the motor,the unit will dock the assembly and the door should open.
it thinks it is playing a tape and that is why the eject doesnt work

try factory restore settings

Try pushing the eject button while pusshing the power button. Mine was doing the same and that is how I was able to eject the tape.
Good luck
sam