# Black dot in desktop (Mojave Mac). What is it?



## Nick Batzdorf (Mar 25, 2020)

This is the most horrible thing that's ever happened to me in my life - a black dot on my Mac desktop.

It's not a dead pixel - you can see in the picture on the right that it goes away when I cover it with another window. And other virtual desktops don't have it.

Replacing the desktop picture, restarting... no help.

WHAT IS GOING ON AND WHAT SHOULD I DO?!!!!!!!!


----------



## Dewdman42 (Mar 25, 2020)

That is weird. did you try a different desktop picture?


----------



## Nick Batzdorf (Mar 25, 2020)

Yup, that doesn't remove it.

It's very weird.


----------



## Dewdman42 (Mar 25, 2020)

I'm sure you tried this already, but reboot?


----------



## kclements (Mar 25, 2020)

I think it’s a dead pixel, sorry to say. does it go away no matter what color window you put over it? Is it possible the grey window just masks it. What happens if you put a light color window over it?


----------



## Dewdman42 (Mar 25, 2020)

when he drags the grey window over the top of the area, its not black anymore. Also its quite a bit larger then a single pixel.

I think that is something else.


----------



## Nick Batzdorf (Mar 25, 2020)

kclements said:


> I think it’s a dead pixel, sorry to say. does it go away no matter what color window you put over it? Is it possible the grey window just masks it. What happens if you put a light color window over it?



It's 100% not a dead pixel. When I swipe to another desktop, it's gone.


----------



## kclements (Mar 25, 2020)

Maybe, hopefully. but I’ve seen 2 pixels that would light sometimes and not others. so just trying to rule it out by trying different color windows, both dark and light. If you leave the grey window there for a bit, does it come back?


----------



## Dewdman42 (Mar 25, 2020)

Something like that is weird, I honestly don't have a good explanation.. I guess its possible its a software glitch. its also possible that its bad memory somewhere, maybe in the video card itself. After reboot if its still in exactly the same place with the same behavior then it would not be your main memory, but could be vid card memory or something where it caches the desktop background.


----------



## kclements (Mar 25, 2020)

Ah, ok. Hmmmm. Very strange.
But I have to ask, if you leave it on that desktop for a while does it return?


----------



## JJP (Mar 25, 2020)

I don't know what this is, Nick, but it creeps me out.


----------



## kclements (Mar 25, 2020)

Yeah, it’s very strange. I don’t mean to doubt you, just trying to rule out everything. Can it be something with the refresh rate of the vid card? What Mac is this?


----------



## nolotrippen (Mar 25, 2020)

Try shutting down your Mac, unplug it from the back (not the wall) and wait a minute or two. Plug it back in. Restart and zap the pram a few times. Good luck.


----------



## Nick Batzdorf (Mar 25, 2020)

Again, if I slide over to Desktop #2 or higher, it's gone. It also doesn't appear on my second monitor.

This is definitely software.

I never noticed it before, but I did just install the latest security update to Mojave, so maybe that's related.

Or maybe I just never noticed it.


----------



## Nick Batzdorf (Mar 25, 2020)

nolotrippen said:


> Try shutting down your Mac, unplug it from the back (not the wall) and wait a minute or two. Plug it back in. Restart and zap the pram a few times. Good luck.



Yup, I already did that.

Thanks though!


----------



## Dewdman42 (Mar 25, 2020)

try swapping the video card if you have one.


----------



## Dewdman42 (Mar 25, 2020)

also what happens if you change resolutions?


----------



## Nick Batzdorf (Mar 25, 2020)

I don't have another video card, and nothing changes if I switch resolutions.


----------



## gamma-ut (Mar 26, 2020)

I had a vertical black line on the desktop image occasionally - I think it was just a bug in the routine that resizes it for the target display.


----------



## robh (Mar 26, 2020)

Nick, if I recall you use SwitchResX, correct? perhaps something weird related to that?


----------



## Jack Weaver (Mar 26, 2020)

Some people have too much time on their hands...

.


----------



## Dewdman42 (Mar 26, 2020)

I use SwitchResX and never had that problem and seriously doubt that is it. SwitchResX doesn't take over all the graphics handling, its just a nice gUI to configure OSX graphics handling with. All the stuff happening is in OSX, in the video driver and the video hardware.


----------



## robh (Mar 26, 2020)

Jack Weaver said:


> Some people have too much time on their hands...
> 
> .


Oh Crap! A white dot just appeared two lines below the capital S!


----------



## Nick Batzdorf (Apr 24, 2020)

Update: the horrific black dot isn't there now.

I'm using SwitchResX too, by the way.


----------



## Jack Weaver (Apr 24, 2020)

Horror averted!!

.


----------



## JJP (Apr 25, 2020)

:emoji_new_moon:


----------



## re-peat (Apr 26, 2020)

If it returns, inject your Mac with disinfectant, Nick.

_


----------



## Markus Kohlprath (Apr 26, 2020)

Hm... what I heard is that also managing to get a lot of light into the computer somehow might help in such cases....


----------



## Nick Batzdorf (Apr 26, 2020)

I'm having a hard time sitting after this anal bleaching.


----------

