How do you open up a dect 4040 .......we have sticking keys. can only open the battery compartment

The video shows one way, but the easy way is open it with the back up key, and the battery compartment is in the door. Replace the batteries and reset the combination, but make sure you do it with the door open.

ELECTRONIC DIGITAL SAFE

UserManual.wiki https://usermanual.wiki > ... PDF Slide the Battery Cover off of the Battery Compartment, remove used Batteries, and insert four new "4, AA" Batteries. Once you have changed the Batteries, be ...
4 pages

wrong site notify locksmith

Amazon.com: Customer Discussions: battery installation for remote ...

www.amazon.com/forum/kindle?_encoding...

Amazon.com, Inc.Jun 11, 2014 - As strange as it may seem to everyone else I cannot figure out how toopen the remote for my Kindle HD TV to put the batteries in.

Amazon Fire TV Stick: How To Open The Remote's Battery ...

? 0:44
https://www.youtube.com/watch?v=F__fFr7nZOE
Nov 30, 2014 - Uploaded by The App Store Chronicle
Here's how to put the batteries into the remote for the new Amazon Fire TV: ... Amazon Fire TV Stick: How To Open TheRemote's Battery Door.

Open Amazon Fire TV 2015 remote battery compartment ...

? 2:35
https://www.youtube.com/watch?v=FyTHjZu3L6M
Oct 6, 2015 - Uploaded by sfsilicon
I am not responsible for any damage to your remote. Proceed with caution. This video shows you how to open ...

If you can get the door open.

There is a reset button on the hinge side of the inside of the door.

Press the reset button, and then you have about five seconds to enter your new code.

Test the code with the door open!

That way, if it does not work the first time, then the doors is still open, and you can do it again.

Warning: Place fresh batteries into the battery compartment before doing this, or you will just get locked out again.

If, you cannot get the door open, and your keys are locked in the safe, then call Harbor Freight.

Call Harbor Freight:
Technical
& Parts (Safe Keys) 1-800-444-3353
Give them the key code number. (it is located on the key insert, where you stick the key in the lock)
It takes about two weeks to get a new key/keys.

This may have been solved by now however...
REMOVE MAIN BATTERY... Before Opening any compartments!
The CMOS battery is located in the modem compartment.
Place the unit upside cown with the rear connectors facing towards you. It is the compartment on the right rear corner (i-screw to remove). It may be difficult ro open due to the modem labe sticking to the cover. Use care when attempting to pry door open.
Battery is CR1220 0.5in Diameter (Dime Size) (40mAh Rated).
Alan

Have you tried to adjust the contrast on your display? If that doesn't help chances are its your battery.
how to change battery:
Remove the battery compartment door, the bottom half of the back, should slide down.
Disconnect the cord attached to the battery pack and remove the battery pack from the handset.
Insert the new battery pack and connect the cord to the jack inside the battery compartment.
Put the battery compartment door back on.

please see on cd drive u seen 1 small hole insert small stick in open tray .

It doesnt use a key , that is just for looks. You will need to open the compartment that the front grille is attached to to locate the battery compartment. 

Underneath the mouse the little compartment that holds the usb stick can be removed to reveal the battery compartment.