Chosen Solution

I have an Acer S231HL monitor. It was having a problem where it would turn on and work after flickering on and off for a while, but after turning off due to standby or powering it off, it wouldn’t come back on unless I’d unplug the HDMI cable for a while.

I opened it to look for any blown capacitors, and during a test power run, I’m pretty sure I accidentally bridged connections on the boards by not elevating them from the back (the screen was face down with the boards sitting on its metal backing plate), because when I turned it on the power light was flickering. I stupidly lifted the inverter board off the back metal plate of the monitor while this was happening instead of turning it off first, and now the monitor doesn’t turn on at all. No power light or anything. I’m guessing I shorted something on the inverter board when I lifted it, and from what I’ve read, replacing the inverter was the solution to the initial issue as well. Here’s how everything is situated when the monitor is fully assembled (the button board in the top-left there sits in the bezel normally):

Here’s how the boards sit in their caddies, which i assume are supposed to put space between the boards and backplate of the LCD, as well as act as grounds:

Here’s how everything was situated for the test run, except obviously the screws weren’t there and everything was plugged into each other properly:

Mainboard:

Inverter board:

Backs of both of those boards:

Does anyone know if I need to replace the inverter board, main board, or both?

I don’t know if anyone is still checking this but I had this same monitor. I also was having screen flickering issues were it would go black and the Acer logo would flash in a loop.Unplugging and replugging gave temporary relief but ultimately the issue came back.When checking the power brick I found that it was very hot…not hot enough to warp it or anything but it was hot!I replaced the power brick with a laptop power brick and cord and it the flickering error went away. Hopefully this helps. Try replacing the power supply first.

@adinga hard to say without seeing it. Since you get absolutely nothing from this monitor I would suggest that you start checking the power board first. Your description and your monitors symptoms sound like a bad power board. Post some GOOD pictures of your boards with your Question so that we can see what you see. Adding images to an existing question