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LG's UltraFine 5K Display Becomes Useless When It's Within Two Meters of a Router (9to5mac.com)

The LG UltraFine 5K Display was designed in part by Apple to work with the New MacBook Pro and as a replacement for the Thunderbolt Display, which was discontinued late last year. According to 9to5Mac, the display apparently wasn't designed to work next to routers as it will flicker, disconnect, or freeze computers when it's within two meters of a router due to electromagnetic interference. The Verge reports: In emails to 9to5Mac, LG acknowledged the problem -- which LG says isn't an issue for any of its other monitors -- noting that routers "may affect the performance of the monitor" and that users should "have the router placed at least two meters away from the monitor" to avoid issues. Once the monitor was moved into a different room away from the router, 9to5Mac says the issues subsided. Despite the fact that it's insane to require a router to be far away from what is likely the main computer in your home, there's been no indication that LG is working on a fix for the issue, which may be more troublesome.

27 of 173 comments (clear)

  1. Problem solved by lucm · · Score: 5, Funny

    users should "have the router placed at least two meters away from the monitor" to avoid issues

    This reminds me of the uuencode bug in Outlook that made the body of the email invisible if the message started with "begin ". The solution on Microsoft's website back then was to use "start" or "commence" instead of "begin" when writing an email.

    --
    lucm, indeed.
    1. Re:Problem solved by msauve · · Score: 2

      In this case "router" actually means wireless access point (some of which also have Internet NAT gateways, which some people call routers).

      --
      "National Security is the chief cause of national insecurity." - Celine's First Law
    2. Re: Problem solved by Z00L00K · · Score: 5, Funny

      How am I now going to do my woodworking?

      --
      If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
    3. Re: Problem solved by arth1 · · Score: 4, Funny

      How am I now going to do my woodworking?

      It only happens with electric routers.
      Use a wireless router, like this one.

    4. Re:Problem solved by FatdogHaiku · · Score: 2

      well, that explains what happened to all my "begin starting to commence" messages...
      At least "prepare to standby" messages worked.

      --
      You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
  2. Shielding? by bussdriver · · Score: 4, Interesting

    Perhaps they don't have proper shielding? or is this a USB-C cable related problem?

    Somebody should experiment by covering it up in various ways and see where the problem is. Start with the cable... since USB-C seems to have not been well thought out.

    1. Re:Shielding? by AmiMoJo · · Score: 4, Informative

      It's not USB-C that is the problem, it's Thunderbolt. USB 3.1 supports up to 10Gb/sec through a USB-C connector. Thunderbolt pushes that up to 40Gb/sec. So naturally cables designed for USB 3.1 compliance are not designed to be run at 4x the data rate, meaning you need special cables certified for Thunderbolt 3 use which look the same and have the same connector as USB 3.1 cables do. Even worse you have cheap USB-C cables and adapters that are only designed for 5Gb/sec or even 0.5Gb/sec.

      Naturally Thunderbolt 3 cables very, very expensive. Therefore people will naturally try to use much cheaper USB cables, and often they will work. The whole thing was a disaster waiting to happen.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
  3. This seems strange by mhkohne · · Score: 4, Interesting

    Given the amount of money and time poured into these products, you'd think they'd have done proper EMI susceptibility at some point. It's moderately expensive, but easy enough for LG to afford.

    If I owned one of these, I'd have to be pushing for them to take it back - there's bound to be other devices that trigger the problem than routers.

    --
    A thousand pounds of wood moving at 300 feet per minute. Don't get in the way.
    1. Re:This seems strange by lucm · · Score: 5, Funny

      Are you talking about QA? This is crazy expensive. To find this bug they would have had to setup a test environment similar to what end users would have; the price tag for that would have been a one-time expense of a thousand dollars, plus labor. There's just no way either LG or Apple could afford that.

      --
      lucm, indeed.
    2. Re:This seems strange by ShanghaiBill · · Score: 5, Insightful

      Given the amount of money and time poured into these products

      Have you ever worked for a big company? It is quite common for product teams to be starved of resources for a number of reasons, often driven by office politics. This was an orphan project dumped by Apple, and I doubt if it is selling well, since no one else is making a USB-C monitor, and this is a 27" monitor, a size that has been available for Macs for 6 years. Every Mac user that wants a 27" monitor already has one, and the extra resolution makes no perceptible difference at that size. If they had actually thought this through, this would be a 30" - 36" 5k monitor that people would actually want to buy.

    3. Re:This seems strange by Lumpy · · Score: 5, Insightful

      "It is quite common for product teams to be starved of resources for a number of reasons, often driven by moron executives"

      FTFY

      --
      Do not look at laser with remaining good eye.
    4. Re:This seems strange by Dahamma · · Score: 2

      Where did LG get a pass? It's required to pass RF transmission standards, not "receiving" interference. The law is to prevent products from interfering with other devices or causing harmful radiation, not sucking as a product. That one's up for the tech/consumer review sites to trash it...

    5. Re:This seems strange by AmiMoJo · · Score: 5, Informative

      5k at 27" is actually the ideal size and resolution.

      The de-facto standard for computer displays is 96 DPI. A 24" monitor with 2k resolution (1920x1080) has around 96 DPI. Everything looks about the right size on screen, the size it was designed to look good at.

      If you move up to 4k then ideally you want 200% scaling. Double every pixel. That way things will at least look no worse than a 2k monitor, and vector images like fonts will be nice and sharp. So 4k at 24" is the ideal. All these 27" and 32" 2k monitors require awkward scaling ratios of 175% or 150% and end up looking crap.

      Apple knows this which is why they always go for 2x the old resolution with their "retina" displays. The ideal 96 DPI resolution at 27" is 2560x1440, which doubled gives you 5k. This monitor is the right size and resolution.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
  4. FTC, not FCC, for two reasons by raymorris · · Score: 4, Informative

    There are two reasons this doesn't run afoul of the FCC rules on harmful interference.

    First, "routers may effect the monitor". The monitor isn't *causing* interference, it's having problems because the *router* is causing interference with the monitor (which the monitor isn't protected against). The "accepting interference" clause means LG (or their customers) can't sue whoever is causing the interference.

    Second, it's actually perfectly legal and normal for your wifi to interfere with mine (or with my monitor) because we're both on the same level, the third-level priority called "unlicensed". What an unlicensed evice may NOT do is interfere with users at the "primary" or "secondary" levels, which are licensed levels. A secondary user, such as a mobile phone operator, may not cause harmful interference to a primary user, such as an ambulance service.

    1. Re:FTC, not FCC, for two reasons by bws111 · · Score: 2

      His statement is entirely correct, and you are wrong. The Part 15 statement, which you are obviously misinterpreting, consists of three parts:

      'Complies with part 15' - means this is an UNLICENSED device, and by design all emissions from the device are within allowable limits. No other requirements.

      'May not cause harmful interference' - means that this unlicensed device may not interfere with any LICENSED operation. Even if the device is operating 100% correctly, if it is causing interference with a licensed operation you must stop using the device or face a a fine. This is not a technical requirement, it is a legal one.

      'Must accept all interference' - means that if ANYTHING is causing interference with your unlicensed device, even if it makes the device unusable, you have no legal recourse through the FCC to make the interfer stop. Again, a legal statement, not a technical one.

  5. You're placing it wrong by OzPeter · · Score: 5, Funny

    In new Chinese year of Rooster, the most correct Feng Shui location for illustrious LG monitor is diametrically opposite the WAP when WAP in same room. If your abode is too small to for this most beautiful solution, retire WAP to original box of delivery and borrow most fine neighbors internet connection.

    --
    I am Slashdot. Are you Slashdot as well?
  6. Re:Router? by PPH · · Score: 5, Funny

    I tried an LG display next to my router. It works just fine, but it gets covered with sawdust pretty quickly. I'm going to test it with the table saw next.

    --
    Have gnu, will travel.
  7. Re: EMC Testing? by Z00L00K · · Score: 2

    Up the stakes with EMP testing for consumer products.

    --
    If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
  8. LG has recommended a simple workaround by uncqual · · Score: 4, Funny

    Elsewhere I read that LG recommended a simple workaround. Just put your wireless router in a Faraday cage and your LG monitor will work fine when it's nearby the router.

    Although they recommend a certified LG brand "Wireless Router Faraday Cage" that they will be launching soon, I understand that Monster Cable will also be announcing one that works better -- something to do with the gold content and balanced geometry apparently.

    --
    Why is there an "insightful" mod and why isn't it "-1"? If I wanted insight, I wouldn't be reading /.
  9. Re: Not the only problem by Imrik · · Score: 3, Insightful

    You won't die of cancer from either of those, (unless the radar is putting out something else in addition to the detection radiation) you might die from your brain boiling or lead poisoning, but not from cancer.

  10. Electromagnetic Immunity by Plocmstart · · Score: 5, Interesting

    I get to deal with weird stuff like this at work all the time. Based on the behavior, I'd guess there's a clock and/or data running at a harmonic of the wifi data. Freezing seems to indicate it's coupling into the core of the LCD controller board, which again I would guess is a timing violation or data corruption. Where it's coupling in is a bit hard to determine without further testing. It could be the video cable, could be the power cable (not likely), could be the LCD panel itself acting as an antenna, or an interconnect cable that is poorly shielded or just the right length to couple in wifi. It could also be power supply ripple caused by a feedback loop getting energy coupled in, though if that's possible then there's not enough timing margin to begin with.

    I suggest a number of tests to narrow down details of the source:
    - Test 2.4GHz and 5GHz independently. Test each wifi channel independently.
    - Try a different length cable. Try a different brand cable. Does this monitor remain on with nothing connected? If so then try it with no cable, or no PC at the end.
    - Try different antenna angles. Try different TX power levels (at what level does it start).
    https://tech.slashdot.org/stor...
    Based on those results I'd have more recommendations.

    If someone wants the real root cause, feel free to send me one and I'll debug it (though it will probably require disassembly).

  11. Compliance failure by ukoda · · Score: 5, Interesting

    As someone who has produced a few products sold around the world I can't see how this monitor reached the retail selves. To sell you generally need to pass immunity and emissions compliance test to FCC or CE standards depending on the market. Emissions means you don't transmit signals above a specified levels and immunity requires your products are not affected below a specified level. The levels vary with frequency and standards but generally the immunity threshold is several magnitudes higher than the emissions thresholds for non-transmitting devices. The WiFi device is an intentional radiator so is allowed higher emissions levels, at it operating band, but immunity levels for the monitor should be able to handle it easily.

    It sounds like a clear failure of the LG monitor and if the nature of the failure reported is correct it sounds like it is not up to standard for immunity. Assuming the problem reported is in the USA then it will be the FCC standards that apply. If I was an owner of an affected LG monitor I would be demanding a copy of the immunity compliance test report. The test report will document what power level was used for the WiFi frequencies and these can be compared with the legal limit for WiFi devices.

    Bottom line is this should never happen on modern products. I know my teams have spent many hours modifying product designs to ensure compliance before we release to market. If LG have not done this then they need to step up and fix the problem at their expense, before the FCC demand a product recall.

    1. Re:Compliance failure by AmiMoJo · · Score: 2

      CE and the relevant FCC bits are self-certified. If your product is not an intentional radiator (i.e. it doesn't have any kind of RF transmitter in it) then you can just self-certify that it has the required level of shielding, doesn't accidentally radiate too much and shouldn't catch fire if you put a wifi router next to it.

      You only need to get it externally tested if you are deliberately transmitting, which the LG monitor is not. It is likely that they never bothered to test it, because they have established designs for monitors and the only things unique about this one are the 5k LCD panel and the Thunderbolt interface.

      I'd guess that the Thunderbolt interface is the problem. It's probably susceptible to 2.4GHz interference. It is after all a very high speed, low voltage link. 5k/60Hz requires around 32Gb/sec.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
  12. Re:Router? by arth1 · · Score: 2

    Yep.

    "This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation ."

  13. Re:Why is it insane for the router to be far? by arth1 · · Score: 2

    Ethernet was not designed to avoid the problem of RF interference.

    Well, yes, that was exactly what it was designed to do. The first implementation, 10base5, had coax cables with extra braided shielding precisely for that reason.

  14. "Including undesired operation" by raymorris · · Score: 2

    Read it again, paying careful atttention to the part after the comma:

    (2) this device must accept any interference received, including interference that may cause undesired operation.

    It says that while interference may cause "undesired operation" (the device doesn't work right due to interference), you have to accept that as part of using unlicensed bands shared with other users.

    It does NOT say "must never exhibit undesired operation". It says the device may exhibit undesired operation, and you have to accept that fact.

  15. Brings back memories by ArhcAngel · · Score: 2

    I was working with a customer on an issue with their new Sceptre 14" CRT monitor some years back. The thing just would not sync. It looked like the scrambled signal you would see when you were trying to watch HBO and you didn't have a subscription (or one of those descramblers you got out of the back of a truck somewhere). After hours without success we called Sceptre support. After describing the problem they advised us we needed to point the monitor due North to align with the Earth's magnetic poles. Once we got off the floor from laughing I went about determining due North and swivel the monitor thus. The picture cleared.

    --
    "A person is smart. People are dumb, panicky dangerous animals and you know it." - K