devils triangle elevator

Im having trouble figuring out how to get the elevator running on the island. Does anyone know what i might be overlooking or doing wrong.

Copied from the walkthrough:

Elevator

1. place the belt on the machine in the back

2. examine the box and place the knob on it

3. next to each knob are letters – they match the letters from the mailbox

4. compare the letters and numbers

5. turn the knobs accordingly

6. solution: ME = 600 | AS = 450 | UR = 150 | E = 300

7. enter the elevator