Potential voltage regulator issue

Hello everyone,

I am just looking for some advice so that I can be more certain of an issue before I try to fix it.

The issue is that a program I have downloaded to an Uno board is no longer working. To be more descriptive, the LCD display that I have connected is not displaying anything but the basic green light - there is a pot connected to a pin (forget which) which affects the contrast before anyone suggests that. Furthermore, the program doesn't appear to be working in any other respect.

I have checked the circuit in an attempt to identify the issue. In this process, I discovered that the supply was 15V: 3.5A, which I believe to be too much. I, therefore, suspect that the issue might be a broken voltage regulator - the one on the board is an AMS1117. However, there does not appear to be any obvious proof of this - whenever I have broken one in the past, there has been some obvious damage to the exterior of the voltage regulator. Furthermore, I am still getting a regulated 3.3V and 5V output of the necessary pins, so I'm now doubting if it is or is not broken.

If any knows of any tests that I can do to prove that the voltage regulator is broken or not and if anyone can suggest any alternative issues that would fit the bill, I would be vert grateful


P.S. Unfortunately I can't provide any diagrams or images of the circuit/board at the moment.

If you are getting th ed correct voltages, the problem is not the regulator (though with 15v input, you can draw very little current without overheating the reg)

The LCD is one of the 1602 or 2004 character displays? You know to adjust the contrast so the powerup pattern is one row blank and one row of solid boxes, right? Does that row of boxes show while sketch should be running, or does it go away (which would indicate that at least some commands to the screen were working)