On the 2nd stage of chapter 7: gateway you can see some screen shot of the previous chapter which will be used as guide for password and numbers

Doors and Rooms Level 7-2 Walkthrough
solve the “hospital” and color screen for the key to open the box
or you just try and error for each arrow to get a serial numbers
use T=2 for OPEN for the last password

doors-and-rooms-walkthrough

doors & rooms stage 7-2 solution :
look on the big screen, it’s the hospital stage 3-1 and the answer is for the door is ambulance color : yellow green red blue
click the table screen and connect the number for yellow – green – red – blue
and enter the numbers
check out the start and exit, use the O as your way out and ignore the X :
right, down, down, right right, up, right, right, down, down, left, down, down, right

click the box with blue light down arrow
press the way out with the arrow
get a serial number card

pres the table screen with 7-2 chair
use the card on serial number printing, and get the card back
observe to see the numbers : 860804
check out the screen for another hint :
OPEN with T=2

pick up a hammer on floor
break the glass of fire extinguisher
dismantle it on inventory and use it to put out the fire off
get the paper, and observe it for the code OPEN
A x T = 6
If T=2, that means A=3
Then you go up and see that A x E = 24, which means E
do the math and you will get 7958 for OPEN

click the exit door screen panel
enter the serial numbers : 860804
then enter the password for OPEN