high sierra overscan issue

The same overscan issue occured after installing High Sierra update when using a Mac mini set up and a HP 23xi monitor. I've found the solution is to use the HP monitor controls (the bottom right buttons found on the monitor itself). Go into menus and find Image Control then Custom Scaling to switch the Overscan control from Auto to Off.

There doesn't seem to be a solution to be found from within the Apple software though a workaround is to go to Settings each time you logon, then to Resolution and select Scaled. Then select 1600 x 900 (which corrects the dimensions) and then select 1080p.

While this works for HP23xi and Mac mini (2012) it may be different for other monitor set ups, but if possible try addressing the display problem through the monitor's own controls and not the Apple software.

I'm also seeing this on a Mac mini connected to a TV. It only happens in the vertical direction for me. Maybe 2/3 of the dock is off the bottom of the screen and the menu bar is completely off the screen. The first couple of times it happened, I rebooted to fix it, then I realized I could change the resolution in system preferences to fix it.

Other posts suggested changing refresh rate to 50Hz - and believe it or not, that seems to fix the overscan issue. What a strange little bug!

It makes no difference to the overscan issue whether it's set to 50 or 60Hz for people using the HP 23xi monitor, which was often shipped in a package deal with Mac mini in the UK. Leaving the setting on the 60Hz factory setting seems to give a slightly sharper and preferable display.

The main solution for getting back a proper dimensioned display for this monitor is to switch off 'Auto' in the monitor's Overscan menu. You do this using the monitor's own controls (buttons bottom right) and set it to 'Off' instead. This monitor will then wake up with the correct display from both Sleep and Restart.

For Apple's information, this bug only appeared after High Sierra 10.13.2 update. It seems to mainly affect HP monitors.

Same issue. Using MacBook Air with Viewsonic VX2433 external monitor in mirror mode. Was working fine for the past several year, then when I upgraded to High Sierra started periodic overscan on Viewsonic monitor. Connecting via HDMI cable through a Thunderbolt hub. Whenever the Mac goes to sleep, or is turned off, or disconnected from monitor then reconnected, it seems to reset the Viewsonic to AV mode instead of PC mode. Can manually reset, but end up doing this several times a day. Called Viewsonic tech support; they determined it's not the monitor, suggested an issue with OSX High Sierra. Just installed OSX 10.13.3, so most current software. No change. Hope Apple makes note of this and can issue a fix.

Unfortunately I can't help as I have been having a similar problem...just hoping that more posts on this thread might lead to someone noticing and trying to do something

I have a mac mini late 2014, Os High Sierra 10.13.3. Up until a few months ago, my computer would occasionally wake from sleep and the screen would be shrunk, then I would open the settings, use the underscan drag bar to fix it, and was good to go for another few weeks. That was with an HP 25vx monitor. Then a few months ago the underscan ruler disappeared from settings, and sometimes I was able to fix it with my monitors built in settings, but not always. Now I have an ACER SA 230 and the problem is still happening.

The apple support website (About overscan and underscan on your Mac, Apple TV, or other display - Apple Support) shows "how to fix" this, except the image it shows includes the underscan ruler....which I no longer have on my computer - I find this moderately infuriating.

I too am having this issue only since the update. I have a Mac mini 2014 and connected to an Emerson 32” tv/monitor. All other details are the same as those above except my Emerson doesn’t have any scaling options in the settings. HELP APPLE!

I have this issue as well but I'm using the TV as a second screen on my MacBook Pro for displaying keynotes or media on a much larger screen. There used to be an overscan slider at the bottom we could use to correct over and under scan issues but slider is now missing in MacOS High Sierra. As far as I can tell, this has not been addressed. 2/23/2018.

Tell us what happens exactly and what you are doing when you experience this issue.

It's almost as if Apple has introduced something that affects anyone not using a full iMac set up with an integrated screen. All those reporting problems seem to be using a Mac mini and a third party monitor. Hopefully we might get a fix in the next update but I'm not holding my breath on this.

This is happening to me with a Mini 2012 hooked up to a Panasonic Plasma. Also happens when I hook my laptop up via HDMI. Lame. Never used to happen before the latest and 'greatest'....

Come on Apple. This is really annoying as it's been around since at least October.

I have the very same problem. Never had this before till I updated the OS

Happens to me on a Mac mini 2012 in 10.13.2 connected to a TV. Not only when it goes to sleep but also sometimes when switched between a full screen program and desktop.

Ive got the same issue. Got my Mac mini hooked up to a 55” LCD. So annoying. Come on Apple !!!!

Same issue here. Still no fix as of Feb '18.