I own a stanley garage door opener recently installed a new travler carrier when adjusting the open & close setting it comes unhooked from the carrier in the upward mode ?

Follow the way given in the video you can able to adjust the door
How to Tighten the Chain on Stanley 7400 Garage Door Opener

Try searching around here to find similar or hopefully exact opener. Stanley no longer is in the garage door business, and the company that bought them out went bankrupt.
Good Luck
http://www.teknuw.com/garage-door-opener-installation-manual/stanley/

Unhooking the wires disconnected the safety sensors completely. The safety sensors are required to close the door. Both lights should be on, the lenses should be able to see each other clearly, and the wires between the sensors and the opener must be intact, in order for the system to function properly. Reconnect the wires to the opener, adjust the aim of the sensors, ensure there is no debris in the sensor lenses, and if it still doesn't work, you'll need a set of replacement sensors.

You have to adjust the safety pressure sensor. It is set to too light a pressure. Check your manual for the adjustment.

THE ADJUSTMENT IS SUPPOSED TO HAVE A 2ND NUT THE TWO TIGHTEN AGAINST EACH OTHER AND ACT LIKE A LOCK

It sounds like the force adjustment may be set too high. Check this:

The force adjustments control the pressure used to open and close the door. A new garage door opener from the factory is set to the lowest possible force adjustment. If you have a properly balanced door, the forces required to open and close the door should be minimal.


The force adjustments are usually located on the rear of the garage door opener and/or under one of the light lenses, If your opener has two lights. If you have lights on the side of your opener, the force adjustment will be located under the right light lens. The force adjustments are labeled with an arrow indicating open or close and numbered 1 to 9, with one being the lowest force and nine the highest. The force adjustments can only turn 260 degrees, or ¾ of a complete turn. Changes to the forces should be done in 10-degree increments. Please remember that too much force will interfere with the proper operation of the safety reversal system. Do not increase the force beyond the minimum required to close the door. Do not use the force adjustments to compensate for a sticking, binding, or unbalanced door.

Hi,
Some of your comments look like they're missing but from what I can see you had to put chain back on and now the door doesn't close all the way.take the cover off and look at the limit switch,this the travel adjustment. The switch for the close side is making contact too soon so it shuts off early.You need to adjust contacts so its further away. Depending on where the trolley was when you reattached the chain, you might not be able to adjust it back enough.But try it first. If you still come up short you will have to take the chain back off and move the trolley back to where the door would be closed and reattach chain. now open position will probably need adjustment leave door unhooked and just let trolley move in case it over shoots the mark either way.

the door beams are not working properly. Let me know what you find

You will need to loosen the chain, This releives the pressure and allows you to make the needed adjustment to the limits (at least 2" from the stop bolt).

SOUNDS LIKE A SENSITIVITY ISSUE UNHOOK THE DOOR AND TRY IT MANUALLY TO BE SURE IT DOESN'T BIND OR IS TOO HARD TO OPEN OR CLOSE.

IF ALL IS WELL CHECK THE SENSITIVITY SETTINGS ON THE BACK OR SIDE OF THE OPENER.

YOU WANT THIS SET AS LOW AS POSSIBLE AND STILL OPERATE THE DOOR WITHOUT REVERSING.

NOTE: THE FULL RANGE OF ADJUSTMENT IS ONLY ABOUT 3/4 TURN SO MAKE A VERY SLIGHT ADJUSTMENT AND THEN TRY IT AGAIN.

HOPE THIS HELPS