My monitor isn't detecting a signal after turning on computer

Your Geforce GTX 1050 Ti may have failed. You need to remove it from the computer and plug your monitor directly to the motherboard video output at the back and see if you get the display to come on. If you do then your graphics card can be bad or even the power supply rail for the card may be dead. Power supply can be tested with multi-meter but if you’re not technical then don’t do it.