关于 Dell U2913WM 宽屏显示器的固件不响应用户操作问题的可能解决方案

鉴于网络上很难找到相同故障的解决方案,我来写一篇文章,以期待有遇到同样问题的人能看到这篇文章。

(English readers please scroll down a page.)

近日我发现一个现象:我手上这台 U2913WM 显示器在使用 DisplayPort 转 mini DP 线缆连接到 MacBook Pro 13′ (2013 late) 时,出现以下问题:

  • 屏幕显示时常有部分长条区域有短暂的不正确输出闪过,尤见于使用 JetBrain 公司的 IDE 时;
  • 在几分钟内可能出现显示内容横向撕裂然后黑屏并且背光不关闭;
  • 使用几分钟到几十分钟后显示器四个触摸按键均不响应任何操作,按电源键虽然无反应但是五秒左右后关机;
  • 电脑关闭显示输出以后显示器黑屏并且背光不关闭,唤醒电脑后显示器无显示。

根据我这三天的实验和猜测,U2913WM 的 DisplayPort 信号解码芯片在输入数据误码率持续过高的情况下会触发 bug,导致所有触摸按键中断和休眠控制失效。同时由于 watchdog 还能正常工作,就出现了按下关机按钮后五秒左右电源能正常关闭的现象。

Dell U2913WM 具有 2560*1080@60Hz 的输出能力,这对信号源和线材都提出了更高的要求。解决方案如下:

  • 使用高质量的支持 DP 1.2 标准的线材(参考 displayport.org 提供的认证线材列表);
  • DisplayPort 线不要和其他强干扰源耦合(远离交流电源线等);
  • 尽量不要扭曲、缠绕、按压、拉扯、摇晃 DisplayPort 线缆和接头处,减少其受力;
  • 玄学问题:同时买两根相同型号的 DisplayPort 线,一定有一根是坏的,另一根会更好一些;
  • 如果不能解决问题,请联系 Dell 客服更换新机。

另外,相对质量较好的线材可以延缓这个 bug 的出现,但不能 100% 避免这个 bug。毕竟电磁干扰的影响因素太多了。


Since there are few information on this problem in English world too (the most accurate one I’v found is on Dell’s official community website, which didn’t have any actual solution), I’ll translate a brief solution here:

Dell U2913WM’s problem of flickering short horizontal colored lines every few seconds / not responding to any user action / not properly go to sleep / won’t wake / switches off after 5 seconds of pressing power button, etc., may be caused by a continuous low SNR from DisplayPort cables of low quality. When your monitor is too busy decoding corrupted data, the bug happens which cause buttons and sleep control module stop responding. There are some general advices:

  • Use a good cable which supports DP 1.2 protocol (Here are a list of displayport.org certified cables);
  • Don’t wind your DisplayPort cable with / parallel to AC power cable;
  • Don’t twist, press, stretch, shake or pull DisplayPort cable or connector;
  • Buy two DisportPort cables of the same model at one time: believe it or not, there must be some magic that when you buy two at once, one cable is bad and another is good. Try them out;
  • If methods above didn’t help, contact Dell support to get a new one.

A cable of good quality may delay this bug from happening, but cannot prevent it at 100% confidence. After all, electronic interference can be caused by multiple factors. 


参考资料 / References:

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