It sounds to me like he is booting the A1200 with no Startup Sequence. Are you holding the 2 mouse buttons down and selecting "Boot with No StartUp Sequence?
If you are, dont............also check if there is a floppy disk in the disk drive......if there is, Remove it as its not allowing the computer to boot. You can Reboot it by simply pressing a combination of keys at the same time...the Keys are:
CTRL Left AMIGA, RIGHT AMIGA (these keys are keys with letter "A" sybols on them on opposite sides of the space bar.............not the letter "A" of the regular keys.
Hope that helps.