Somehow can open my sentry s3877 with the keypad.

You need to look on you tube for this. There are lots of videos on opening that safe with a rubber mallet.

The factory code combination to your electronic lock will remain in the memory of the unit - even if the batteries go dead. Any use programmed codes will be lost if the batteries lose power. The Sentry programmed factory code is always your default code.

If you do not know your factory code, you can follow this link for your combination retrieval:

http://www.sentrysafeshop.com/Lost-Combination-Sentry-Safe-Combination-p/lost%20combination.htm

Use paperclip to push in pin size hole below keyboard and then slide panel to right. Battery box is right there. Replace batteries and then was already to accept code.

Motorola IC #MC68HRC705 will not reset. Chip is most likely bad. Time to throw this safe out...Thanks for your answers. George

The door lock could be jammed try shacking briskly to losen lid and latch! akso it may have reset itself and the combo is no good no more and back to the origanal setting it had when you bought it ! ( if its a 911 you can put a screwdriver in where key goes and turn hard counter clockwise)
Good Luck!

goto SentrySafe.com and request a combination to be send to you.
you need the model and the serial number from the box.

how to change the on sentry safe s3877

I had the same problem with my Sentry S3877. I found the exact 4-battery replacement (with snap attachment on top!) at an online electronics.retailer, but had to purchase a lot of three. I don't need the other two, so I'll sell them for just $6 each to the first two folks to contact me [email protected].

Oh, by the way, once the batteries went dead, you lost your combination! When you pop the new battery compartment in, the factory default combination will be in effect. That default combination is in your user's manual. I'm currently searching frantically for mine! Gee, how could I have misplaced it ... I just had it in my hands when I purchased the safe 10 years ago !!!

Anyone know the default combo for the S3877?

---- Mark