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
105 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
105 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

iOS 19 Mock WWDC25 Feature

iOS 19 Expected to Run on These iPhones

Monday March 31, 2025 5:28 pm PDT by
iOS 19 will not be available on the iPhone XR, iPhone XS, or the iPhone XS Max, according a private account on social media site X that has accurately provided information on device compatibility in the past. The iPhone XR, iPhone XS, and iPhone XS Max all have an A12 Bionic chip, so it looks like iOS 19 will discontinue support for that chip. All other iPhones that run iOS 18 are expected...
maxresdefault

Apple Releases iOS 18.4 With Priority Notifications, Ambient Music, New Emoji and More

Monday March 31, 2025 10:03 am PDT by
Apple today released iOS 18.4 and iPadOS 18.4, the fourth major updates to the iOS 18 and iPadOS 18 operating system updates that came out last year. iOS 18.4 and iPadOS 18.4 come two months after Apple released iOS 18.3 and iPadOS 18.3. Subscribe to the MacRumors YouTube channel for more videos. The new software can be downloaded on eligible iPhones and iPads over-the-air by going to...
watchOS 11 Thumb 2 1

Apple Releases watchOS 11.4 With Sleep Alarm Update

Tuesday April 1, 2025 10:34 am PDT by
Apple today released watchOS 11.4, the fourth major update to the operating system that runs on the Apple Watch. watchOS 11.4 is compatible with the Apple Watch Series 6 and later, all Apple Watch Ultra models, and the Apple Watch SE 2. watchOS 11.4 can be downloaded on a connected iPhone by opening up the Apple Watch app and going to General > Software Update. To install the new software,...
AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 2 and AirPods 4

Monday March 31, 2025 11:27 am PDT by
Apple today released new firmware updates for all AirPods 4 and AirPods Pro 2 models. The new firmware is version 7E93, up from the 7B21 firmware that was installed on the AirPods Pro 2 and the 7B20 firmware available on the AirPods 4 and AirPods 4 with ANC. It is not immediately clear what new features or changes are included in the new firmware, but we'll update this article should we find ...
iPhone 17 Pro 34ths Perspective

iPhone 17 Pro Launching Later This Year With These 10 New Features

Sunday March 23, 2025 10:00 am PDT by
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of March 2025: Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone ...
macOS Sequoia Feature

Apple Releases macOS Sequoia 15.4 With Mail Categorization and More

Monday March 31, 2025 10:04 am PDT by
Apple today released macOS Sequoia 15.4, the fourth major update to the macOS Sequoia operating system that launched in September. macOS Sequoia 15.4 comes two months after the launch of macOS Sequoia 15.3. Mac users can download the ‌‌macOS Sequoia‌‌ update through the Software Update section of System Settings. It is available for free on all Macs able to run macOS 15. With...