I set my new code but it won't open. - Master Lock 1590D Set-Your-Own Combination Lock, Steel, 1 7/8"Wide, Assorted

If you remember the first letter/number you're still in luck. What you need to do is start off with that letter. If you know what you tried to set, ex. ATE

Work with
A
A, D, E, H, J, L As for the last number/letter, all you have to do is keep spinning it right and you will hit it.

For me, I tried fooling around and setting ALT

However, when I was entering the new combo, I turned 3times or more right when key was in to A, then a full circular left turn past A to L. From L, I turned the same direction 4 clicks to T and locked it. I realized I entered it wrong when I locked it. How these locks were designed isn't that complicated. It consists of 3 different turns. Right, left, right. Right to A, left to L, right to T. When I had entered, right to A, left to L, and left again to T. It automatically makes the second letter/digit the same as your first letter/digit. I cracked my lock trying all combinations of A,L,T. Writing a list helps. But I also suggest your write down a list of your first digit twice.

A, A, L A, L, A
A, L, T A, A, T (That's what my code was after incorrectly trying to set it as "ALT")

However, this is only one method. When I had purchased the lock a year ago and set a combination. I approached it with a different method. The first one as I mentioned. I had tried to set EAT to test. The combo ended up being a letter or two off in the combo itself. So my cracked combo was not EAT but something _AT or EA_ or E_T. Combos usually aren't off by a whole lot. I was going to throw my lock away and buy a new one, but I cracked it :) I know this is alot about my own experience, but don't give up! I was planning on solving it, but I did it within 10mins! Not so tough !