My tape deck is making noises while operating.

These dual cassette decks were throw away units in most cases. The belt inside and the grease in the cam mechanism is in bad shape and the deck can not cycle through the steps it need to so as to reach stop. Only stop mode will allow the door block to release. The tape can safely be extracted by a Technician. The deck need work. Dual cassette decks are not always worn the repair cost.

Just change main drive belt in new one.

It can be a number of things. There are some models that are suppose to run the capstan when a tape is in and some unit that only run when the play is pushed. The proper operation and speed as well as cleaning can all be done by a Tape Deck Technician.

We need more than that- brand, model, what kind of noise?

Another dual deck it seems- the unit will need service by a Technician, there is no magic that will make it work. It may be as little as a large belt. I would have to see the unit to tell you the exact cause.

Is it the same tape every time or all tapes? If it is all tapes then it's more than likely a belt issue. The tape players have little rubber belts inside they sometimes get stretched when they are used alot. And they will make a whinning sound. They can be replaced.

Drives belt has become too slack to drive mechanism properly or the drive motor is bad. Have unit serviced for new belt(s)

The belts will have failed. You will need to replace them for the deck to be reliable. If you are mechanically minded I can talk you through it... You giving me a FixYa rating will help my profile and loosen my lips on how to overhaul your deck. :)

most tape decks are designed so that the spindle will run when powered on. when you press play or record, the pinch roller elevates the tape to the spindle, tape starts to travel.

noise is basically from the mechanism, or deteriorated in time as yours is an used one. if you are lucky to find some good pinch roller rubbers of same diameter, replace them.

pc-cook