ASUS PB278Q PC Monitor won't Power on after Pc wakes from rest mode

Hi, I’m facing a problem latetly with my pc monitor, as the title says when the Pc wakes from power saving mode after inactivity the monitor won’t wake up and stays with an orange light. I have a second monitor on the Pc and it wakes up with no problem. This is a new issue as the monitor didn’t had this problem before. Even if I close the Pc and the monitor goes on energy saving mode, after I open the pc it dosen’t power on. I had to puss the power buttom on the monitor to close it and re open it to have a signal in the HDMI.
So Do you think this is a capasitor problem, or a power supply?
Monitor is 9 years old.

Hey,

Yeah, bad caps would be the most likely candidate and most probably on the digitial board, I would guess the PSU is likely fine.

I would dismantle, take a photo of all the caps so you can note their polarity on the board and also their values then remove all of them on the digital board and test with an ESR meter to see if they are in the realms of bad or dying, if you find a few that are bad then I’d just replace the lot as a matter of course with some decent Panasonic ones.

thnks for the reply, I did replace a bad blown cap on an older LG monitor that wouldn’t power on(I fix it), so I guess the teardown is inevitable to check the caps. Thanks again for the info, appreciated.