2 troubles with computer need help

[Apple]

One of my desktop computer is malfunctioning, when I click power button it brightened up, the screen says no signal and the screen remains black my screen is on and it turned orange after displaying no signal.
Basically my computer is running and it doesn't show on the screen at all.
Please help me with this

My laptop is connected to the Internet, and it keep disconnect every now and then when I uses Internet
I use modem and router for the wireless network
Well wireless didn't work, with wires connected it have stable internet access...
tried to use neighbour's internet and it works.
my brother in another country told me to reset router.

[JustANewbie]

maybe you should use only router?

[Apple]

Okay my brother assisted me and guided me to fix it.
lucky to have a computer engineering brother