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
115 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
115 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

iphone 17 models

No iPhone 18 Launch This Year, Reports Suggest

Thursday January 1, 2026 8:43 am PST by
Apple is not expected to release a standard iPhone 18 model this year, according to a growing number of reports that suggest the company is planning a significant change to its long-standing annual iPhone launch cycle. Despite the immense success of the iPhone 17 in 2025, the iPhone 18 is not expected to arrive until the spring of 2027, leaving the iPhone 17 in the lineup as the latest...
duolingo ad live activity

Duolingo Used iPhone's Dynamic Island to Display Ads, Violating Apple Design Guidelines

Friday January 2, 2026 1:36 pm PST by
Language learning app Duolingo has apparently been using the iPhone's Live Activity feature to display ads on the Lock Screen and the Dynamic Island, which violates Apple's design guidelines. According to multiple reports on Reddit, the Duolingo app has been displaying an ad for a "Super offer," which is Duolingo's paid subscription option. Apple's guidelines for Live Activity state that...
Clicks Communicator Feature

'Clicks Communicator' Unveiled — Will You Carry This With Your iPhone?

Friday January 2, 2026 6:35 am PST by
The company behind the BlackBerry-like Clicks Keyboard accessory for the iPhone today unveiled a new Android 16 smartphone called the Clicks Communicator. The purpose-built device is designed to be used as a second phone alongside your iPhone, with the intended focus being communication over content consumption. It runs a custom Android launcher that offers a curated selection of messaging...
apple intelligence black

Report: Apple's AI Strategy Could Finally Pay Off in 2026

Tuesday December 30, 2025 9:01 am PST by
Apple's restrained artificial intelligence strategy may pay off in 2026 amid the arrival of a revamped Siri and concerns around the AI market "bubble" bursting, The Information argues. The speculative report notes that Apple has taken a restrained approach with AI innovations compared with peers such as OpenAI, Google, and Meta, which are investing hundreds of billions of dollars in data...
Low Cost MacBook Feature A18 Pro

Low-Price 12.9-Inch MacBook With A18 Pro Chip Reportedly Launching Early This Year

Friday January 2, 2026 9:08 am PST by
Apple plans to introduce a 12.9-inch MacBook in spring 2026, according to TrendForce. In a press release this week, the Taiwanese research firm said this MacBook will be aimed at the entry-level to mid-range market, with "competitive pricing." TrendForce did not share any further details about this MacBook, but the information that it shared lines up with several rumors about a more...
apple fitness 2026 1

Apple Teases 'Something Big' Coming Soon to Apple Fitness+

Tuesday December 30, 2025 2:11 pm PST by
The Apple Fitness+ Instagram account today teased that the service has "big plans" for 2026. In a video, several Apple Fitness+ trainers are shown holding up newspapers with headlines related to Apple Fitness+. What's Apple Fitness+ Planning for the New Year? Something Big is Coming to Apple Fitness+ The Countdown Begins. Apple Fitness+ 2026 is Almost Here 2026 Plans Still Under ...
Apple Fitness Plus hero

Apple Announces New Fitness+ Workout Programs, Strava Challenge, and More

Friday January 2, 2026 6:43 am PST by
Apple today announced a number of updates to Apple Fitness+ and activity with the Apple Watch. The key announcements include: New Year limited-edition award: Users can win the award by closing all three Activity Rings for seven days in a row in January. "Quit Quitting" Strava challenge: Available in Strava throughout January, users who log 12 workouts anytime in the month will win an ...
Mac Pro Feature Blue

What's Happening With the Mac Pro?

Wednesday December 31, 2025 9:59 am PST by
Apple hasn't updated the Mac Pro since 2023, and according to recent rumors, there's no update coming in the near future. In fact, Apple might be finished with the Mac Pro. Bloomberg recently said that the Mac Pro is "on the back burner" and has been "largely written off" by Apple. Apple apparently views the more compact Mac Studio as the ideal high-end pro-level desktop, and it has almost...