iMac 27 inch 2020 - Screen Glitch (Random Lines Appear on Screen)

I feel just like you. I’ve been waiting patiently for a new iMac as I’m using a very old windows machine now. I was so excited for this and now am disappointed.

I just went for the 5700 instead of the 5700XT as I am not a gamer anyway. I wasn’t about to buy something that May or may not have a hardware issue.

cant wait for it to show up. Maybe you want to also consider stepping down to the middle graphics card.

I really hope it’s not making constant fan noise as well.

I had a late 2015 that is still working great but I wanted to upgrade and so I ordered a top spec. I am disappointed by the constant fan noise. I don’t always hear it but when the room is quiet I do and it feels like a step back and not worth the $$$$$. I am going to return it tomorrow which is a huge disappointment and hassle. I may order another lower spec iMac if people report that they are silent.

Also the anti glare was not worth it for me and it does degrade the image. Only get it if your lighting conditions call for it.

I am curious to find out what the process of returning the iMac 2020 considering non of the Apple stores is open due to COVID? I received my system three weeks ago, and the white horizontal lines are increasing & moving to different parts of the right screen. My iMac 27 is fully loaded and was a significant financial investment for me. Really disappointed that Apple is not owning this problem and getting in front of it.

Where are you? There a lots of Apple Stores currently open at least as "storefronts" (pick up and, don't know, maybe drop-off, too?) in the US: https://appleinsider.com/articles/20/05/25/heres-where-apple-stores-have-reopened-around-the-world.

Apple tends pretty much never to admit in, say, a press release that there's hardware flaw, even after they've diagnosed it and have a free repair program. At some point, that information just becomes available through AppleCare and the Genius Bars — and this the net. If it's a software issue, that'll probably get mixed into "an upcoming release" of the OS. 11.1? We can hope.

I'm so confused... some people are so disappointed with the fan noise, even to the point of returning it for that reason, and yet others are also saying "it's really quiet" and can "hardly hear it at all!". I haven't ordered my iMac 2020 yet, but I'm just not sure what to make of it!?

I'm not experiencing this at all on my end with a very specific setup. Perhaps your graphics card became slightly dislodged during the shipping process? I have a similar setup to you, but absolutely no issues at this point.

There is no graphics "card" in the 2020 iMac 27-inch. There is a soldered-on chip, which is cooled by the same cold finger (copper pipe) and fan as the CPU.

Could you please confirm that you have the same configuration as appears to the one suffering from the screen glitch and possible intensive graphic crash issues, namely the 5700 XT graphic option? Also, which CPU option did you get?

Thanks.

Thanks!

I'm having a hard time envisioning how the chip, held down by a screwed- or riveted-on brace, inside a durable aluminum body, shipped in dense styrofoam (or whatever the CO_2-friendly replacement is called), in a sturdy corrugated cardboard box inside of another cardboard box, is liable to be damaged. For that to happen, you'd have to see the entrance and exit holes made by the 20 mm round. ;-)

Frankly, it's more likely there's a bad batch of chips, as there apparently was with the 2011 27 high-end graphics option, as michaeloupatrick says, a software issue. There could also, I suppose, be a graphics memory issue, since presumably the higher (full) resolution gets into higher graphics option memory sooner.

Having the same issue on my 2020 with 5700XT 16GB. White lines randomly glitch or flash, and corners of certain windows randomly fill in the rounded edge with blank pixels. The problem only appears to happen when the display is on the default resolution.

Just got my replacement iMac from Apple yesterday and it too has the same glitch issue (AGAIN)... I have the nano textured 27", 10 core i9, 4TB SSD, 128GB Memory (OMC's not Apple - too expensive and ripoff), 10gb Ethernet, and 5700 XT 16GBN. The first day was no glitches, then the second day (today) glitch's every 10 minutes.. I naturally tried the resolution changes and so far that seems to address the issue, but also heard that a secondary display also stops it. You can add some custom resolutions which also seems to work, but i was looking at getting a secondary 4k display anyhow so i opted to order one online from LG.

I can confirm the resolution change and/or dual display corrected my issues from what i can tell so far... (if that changes i will post an update), but so far so good.

The reset of the NVRAM and SMC work, but only temporarily (Sometimes not at all).

I am having the same issue now with TWO identical computers. The first one I ordered had this issue in its initial setup. Apple advised I return it since I was within the two week window. I am still waiting for a "senior advisor" to call me because they accidentally created it as a replacement instead of a refund. I had to shell out more money to get a new one because I was up against a project deadline -- now this new one is having the same exact issue! I am on the phone waiting to speak to someone as we speak. Absolutely unacceptable.

Just got my new iMac this morning. Here's my setup:

8-core

5700XT 16GB

Corsair 128GB RAM

1TB SSD

I've had it on for about 8 hours or so, haven't noticed any glitching or tearing during run-of-the-mill operation. Just a thought bubble: could it be the combination of the 10 core and the 5700XT? I'll post back if the glitching starts happening.. my sympathy for everybody having this issue.

Yep! This has started happening to me now after only a few days of use! Oddly enough, it started happening while I was listening to YouTube in the background and working on some writing in Pages. I thought I noticed it while playing DOTA 2 on Steam yesterday, but I brushed it off because I was pretty engaged in the game. However, it's much more obvious when I'm just working on a Pages document.

Can confirm I have the AMD Radeon Pro 5700 XT 16 GB, the 10-core configuration, and 64gb of RAM.

Well After getting my replacement iMac.. I am running into the same issue but now have greater issues...

It locks up (beachball icon, then clock freezes - after a few seconds it reboots and i get a black screen with a message stating "Your computer restarted because of a problem..."

It has done this 4 times today resulting in a substantial loss of work, I cannot use this for school or work..

At this point the best options is to send it back. This means that 2 new iMacs (First one, and then the replacement) both have issues, but this second one in my opinion is worse, so I am now opting for a refund.

There is clearly some issues with the 27" 2020 iMac with the 5700XT Card... I have the 16 gb model with 128gb

It started with Glitches, Then True Tone refresh issues, Beachball icon and intermittent lockups and now unexpected reboots.

I personally don't want to know what's next... This think is as stable as mentos and coke...

Hoping they figure it out soon so I can order one that works, it glad to hear the 5700 is fine.. so far it seems to be just isolated to the 5700xt from what I been reading..

just dropped mine off at FedEx today for the refund