How to switching between INIT 3 and INIT 5

[Stephen Liu]

Hi folks,

5.2
==

Kindly advise the key combination switching between INIT 3 and INIT 5

Ctrl + Alt + F2 = INIT 3/Text mode (works)
Ctrl + Alt + F7 = INIT 5/Graphic mode (does not work)

and the method switching to multi-user-mode from single-user-mode 
instead of rebooting PC

TIA

B.R.
Stephen Liu