Hello, and welcome.
The first thing I would do is change the batteries; that's usually the problem in these cases. Use only alkaline or lithium for electronics batteries and never use rechargeable.
If that doesn't work, check that your combination is the correct one and you can consult your manual for that. If you don't have your original manual, you can request one from Sentry, here:
Phone:(###) ###-####br />Fax:(###) ###-####/strong>Hours of Operation:Monday - Friday, 8am - 6pm EST
You can also try striking the door above and below the keypad, carefully, with a rubber mallet or hammer with a towel wrapped around the head. Also, strike the safe around all edges and the top. Put pressure on the upper left hand corner of the door, as if you were closing the safe--lean into it. It's also possible that something is blocking the actuator (opening mechanism) inside, if some inside contents shifted. Try tilting the safe to the right side and to the back (with help, if necessary, so you don't hurt yourself).
Your handle or opening mechanism may be defective and you will need to discuss that with Sentry at the Customer Service number I listed, above.
Please remember you have only 4 seconds to turn your handle down from the horizontal position, after entering the code and you can't take more than 5 seconds in between entering the numbers of the code.
Try all of these suggestions and please let me know if they are helpful.
Please be so kind as to rate my answer with positive feedback; that is the only way I receive credit for my assistance. Thank you very much!Providing a positive rating will not end our conversation, should you need me for any follow-up. Simply click 'Reply' for clarification or additional information, if needed, at no additional charge.