Last week, we shared a brief video showing that LG's revisions to the shielding in the UltraFine 5K display have successfully addressed issues with the display flickering and disconnecting when in close proximity to Wi-Fi routers. Apple and LG had temporarily pulled the display from the market while LG adjusted its manufacturing processes to incorporate the fix and push the new stock into sales channels, and sales of the revised display began earlier this month.

At the time of last week's post, we noted that customers purchasing the UltraFine 5K display should check for serial numbers beginning with 702 or 703, as these indicate manufacturing dates of February or March after the fix was put into place. Several MacRumors readers subsequently reported, however, that they have recently received units shipped from Apple with serial numbers starting with 612, indicating manufacturing dates in December 2016.

These readers have been uncertain as to whether their units have the revised shielding in place, or if they should be testing their displays to see if the flickering issue can be induced. One reader noticed that the label on the box of his December UltraFine 5K included a black circular sticker at the top left, a sticker that was not present on our original UltraFine 5K display that was manufactured in November and shipped in December and which was susceptible to the interference issue.

ultrafine circle square fixed

December 2016 unit retrofitted prior to sale (left) vs. March 2017 unit properly shielded from the start (right)

Newly manufactured UltraFine 5K units include a black square printed directly on the label in the same location, and LG has confirmed to MacRumors that the presence of a circle or square does in fact indicate that the unit has the revised internal shielding and should be protected from the interference issues.

While LG did not explicitly confirm any difference between a circle and a square, it appears that the square is indicative of a unit that was originally manufactured with the proper shielding, while the circle is used on earlier units that were subsequently retrofitted with the shielding before sale. There should be no difference in the performance of the two versions.

For those users with units lacking a circle or square on the label and thus susceptible to the Wi-Fi interference, LG is conducting free repairs to install the proper shielding. Users are advised to contact LG to arrange for the repair, which can take up to 7-10 business days once the display is received by the repair facility.

Customers interested in purchasing the UltraFine 5K should remember that Apple's 25 percent discount on USB-C and Thunderbolt 3 accessories is still scheduled to end on March 31, so they have just over a week to order the display at its discounted price of $974 before it goes back up to its regular price of $1299.95. It is possible Apple could extend the discount as it has done once already, but there are no guarantees.

Tag: LG
Related Forum: Mac Accessories

Top Rated Comments

craig1410 Avatar
113 months ago
That circle / square sticker thing seems to stack up. As expected, my 701s are both circles. But yeah, I still won't be returning them, as there are no obvious indicators now that these displays are inferior in any way to "square" models. Maybe when I go to sell these on eBay in 5 years, my dreaded "circle sticker" will knock $50 off the price though ;)

Still, it's dubious that LG / Apple are selling these circle models as "new". This is almost the very definition of manufacturer-refurb right? Apart from the fact that they weren't necessarily "returned" by customers (unless you count Apple as LG's customer). They've still been opened, refurbished in-a-sense, and repacked.
I think as long as they are "unused" then it's okay to sell as new, even if they were upgraded and repacked.
Score: 1 Votes (Like | Disagree)
Corrode Avatar
113 months ago
Thanks for writing about this. I pick up my fourth display (third replacement) tonight. Hoping for a square!
Score: 1 Votes (Like | Disagree)

Popular Stories

Apple Shopping Event 2025

Apple Announces 2025 Black Friday Event, Here's What You Can Get

Thursday November 20, 2025 6:28 am PST by
Apple's annual four-day Black Friday through Cyber Monday shopping event is returning on Friday, November 28 through Monday, December 1 in many countries, including the United States, Canada, Australia, New Zealand, France, Germany, Italy, Spain, the United Kingdom, Belgium, the Netherlands, Sweden, Thailand, and others. During the shopping event, customers can get an Apple gift card with...
iPhone 17 Pro Cosmic Orange

10 Reasons to Wait for Next Year's iPhone 18 Pro

Wednesday November 19, 2025 4:00 am PST by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models at the same time, which is why we often get rumored features months ahead of launch. The iPhone 18 series is no different, and we already have a good idea of what to expect for the iPhone 18 Pro and iPhone 18 Pro Max. One thing worth...
iOS 26

iOS 26.2 Adds These New Features to Your iPhone

Thursday November 20, 2025 10:50 am PST by
iOS 26.2 is currently in beta testing. The upcoming update includes a handful of new features and changes on the iPhone, including a new Liquid Glass slider for the Lock Screen's clock, offline lyrics for Apple Music, and more. In a recent press release, Apple confirmed that iOS 26.2 will be released to all users in December, but it did not provide a specific release date. Keep reading...
hikawa phone grip stand apple%402x

Apple Launches Second Limited-Edition iPhone Accessory in a Month

Friday November 21, 2025 3:53 am PST by
Apple has begun selling the Hikawa Phone Grip and Stand, a new limited-edition iPhone accessory designed with accessibility in mind. Designed by LA-based Bailey Hikawa to celebrate the 40th anniversary of accessibility at Apple, the grip uses magnets to securely snap onto any iPhone with MagSafe. Apple says it can be removed with ease, and doubles as a stand with two different viewing...
ipad mini 7 feature red and blue

iPad Mini 8: Four Major New Features to Expect

Wednesday November 19, 2025 7:50 am PST by
Apple's eighth-generation iPad mini is highly likely to arrive next year, offering a significant refresh of the device with at least four major new features. OLED Display The next-generation version of the iPad mini could feature an OLED display, as part of Apple's plan to expand the display technology across many more of its devices. Apple's first OLED device was the Apple Watch in 2015, ...
applecare apple care banner

Apple Brings New AppleCare+ Options to India

Tuesday November 18, 2025 8:42 am PST by
Apple today announced an expansion of AppleCare+ coverage in India, with new options for monthly and annual plans, and the addition of Theft and Loss for iPhone for the first time. Options for monthly and annual AppleCare+ plans in India provide more choice and flexibility, allowing users to keep coverage for as long as they require. Apple's vice president of Worldwide iPhone Product...
watchos 26 workout app

Apple Watch Users Claim Workout App Is Now Worse in Every Way

Thursday November 20, 2025 7:01 am PST by
Apple Watch owners have been voicing their frustration online over changes to the Workout app that Apple introduced in watchOS 26, with many finding the redesigned interface makes starting exercises difficult and exasperating. When Apple launched watchOS 26 in September, the Workout app went from large, easily tapped workout tiles to a scrolling, corner-button interface. Instead of tapping a ...
apple wallet drivers license feature iPhone 15 pro

Two More U.S. States Commit to Offering iPhone Driver's Licenses in Apple Wallet App

Thursday November 20, 2025 8:21 am PST by
In select U.S. states, residents can add their driver's license or state ID to the Apple Wallet app on the iPhone and Apple Watch, and then use it to display proof of identity or age at select airports and businesses, and in select apps. Earlier this week, Illinois became the 13th state in the U.S. to offer the feature. Subsequently, we shared a list of additional states that are committed...
android iphone airdrop quickshare

iPhone Users Can Now AirDrop Files to Android Devices

Thursday November 20, 2025 9:47 am PST by
Google today announced a new cross-platform feature that allows for file sharing between iPhone and Android users. With AirDrop on the iPhone and QuickShare on Pixel 10 devices, there is a new file transfer function available. The file sharing option works on Apple devices that include iPhone, iPad, and Mac, along with the Pixel 10, Pixel 10 Pro, Pixel 10 Pro XL, and Pixel 10 Fold....
iOS 26

Everything New in iOS 26.2 Beta 3

Monday November 17, 2025 3:20 pm PST by
Apple provided developers with the third beta of an upcoming iOS 26.2 update, and there are still new features that are being added with each beta that we get. We've rounded up all of the changes that Apple made in beta 3. AirDrop Apple added new AirDrop functionality, providing a way for two people to share files temporarily without having to add one another as contacts. iOS 26.2...