Help my ps2 slim broke

i bought a ps2 off a friend… i tested it at my brothers house and it worked… a few days later it stoped working

the red light stays on if you have it plugged in… but when you turn it on… the green light blinks and shuts off again…

i noticed that the power cord is not the orginal power cord… the cord is a 9 volt

and the ps2 needs a 8.5 but is this the problem? or how do i fix it?

and why did it work at my brother house and not mine?

help im connfused

yeah, you sure as hell need the right supply