No input signal recommended settings hp vs15 monitor 1024x768 60h

Old monitor 1280 x 1024
power light on?
OSD work?
if it said on the screen no input sig, then that is 100% true
the PC is not sending output.

check the video cable connections both ends
then if bad, boot PC to safe mode. does that work.
then maybe you set the PC graphic resolution too high for the monitor. use safe mode to set new , legal resolution
1280 x 1024 is max, do not exceed, the horz, vert, reso to the left here. if you do the monitor , will display, out of range. errors.

im confused, you show HP monitor then Sam.
why ?
my guess is HP question posted in SAM section.
so here is my HP answer
1280 x 768 @ 75Hz

if your PC or other device exceeds any of those. this old monitor
will go blank.
HOR, vert and refresh rates max.

to solve this riddle, set the PC to
1280 x 768
then connect monitor and bingo.
but there is a chicken and egg deal here.
if the display car is over this, as most new systems are.
then use safe mode to set the resolution to 1280 x 768
and reboot to normal mode.
boot and it F8 , safemode.