U2415, Dual, Daisy chain DP1.2 issues

Be sure to update the AMD Radeon HD6870 to the latest driver.

A00 August 24, 2014
A00 August 28, 2014

So this is the setup you are using?

AMD Radeon 6870 mDP out --> UltraAV mDP to DP cable --> #1 U2415 (#4) DP in (DisplayPort 1.2 Enabled)

#1 U2415 (#6) DP out --> UltraAV DP to mDP cable --> #2 U2415 (#5) mDP in (DisplayPort 1.2 Enabled)

yes, all correct except that I use the supplied Dell mDP to DP cable between the monitors. I have to switch the monitors on and off several times before the black screens stop. Note that the OS continues to run in the background despite the black screen. 

No, there was no change. To me the issue seems to be the "handshake" between the master monitor and the pc because the monitor screen is black even though the os has gone through post and loaded. If I then switch off the monitor and then back on the os is running on screen. If I start then start to enter the password and the screen again blinks black the password carries on and is activated and the os runs normally. After switching off/on  the monitor a couple of times the screen stops blinking so obviously the pc and the monitor have recognised each other. The question is how to correct this.

I have run Alien autopsy and all the other checks that you have mentioned in previous responses to other queries but nothing has changed.    

Not sure if this will help at all?

www.dell.com/.../EN

I am currently experiencing the same problem as HowChris though with a slightly different configuration.  Using only the dell-provided cables, my configuration is Laptop_DP->Monitor1_mDP, Monitor1_DP->Monitor2_mDP.

The screen flicker does not appear to affect peripheral connectivity as open windows do not re-position to the laptop screen as if the monitors were disconnected.

Monitor2 currently has DP1.2 disabled as it was suggested that the last monitor in the chain should have it disabled to explicitly identify it as the end of the chain.

Disconnecting the monitors and reconnecting them ends the flickering when it does happen, but this is a huge hit to productivity as not only do I have to stop my work to address the sudden flickering, but on top of that, all open windows get rearranged in the process.  This is far from the ideal solution and frankly should never become an option.

I have been experiencing this problem intermittently for months now and at this point I am fed up with it.  I regret not immediately returning them when it first came up.

customerAW,

What OS, video card, driver version, U2415 revision number and serial number?

I'm experiencing this same frustration. Has a fix been identified? My AMD hd6870 drivers are on the most current version. I have to believe this is a Dell Daisy chain issue as there are many other users with similar symptoms that are using a different graphics.

I am having the same problem with my 2 U2415 A00 monitors daisy chained. In fact, it just started happening the moment I started this reply. :/ I am a software engineer and after diagnosing this on my end I am fairly confident this issue has nothing to do with the computers, cables or anything else external to the monitors. I have found that when this occurs, putting the monitors into power save mode can remedy the problem temporarily. However, it eventually returns. These monitors are not reliable. Does Dell acknowledge there is a problem with MST on certain revs of this monitor?

A00? The A02s came out in February 2015. Getting exchanges should get you A02.

Is this problem fixed in rev A02? I love monitor, just hate this problem. :) Since I hadn't read anything about a fix for the problem, I was holding off on the exchange.

 Unfortunately, that information is no longer published by Dell or provided to us.

I also have a flickering issue with a 3 x U2415 daisy chain setup. Usually only 1 monitor flickers. I have ruled out bad cables or too low bandwidth, because simply turning the monitor off and on solves the problem for the whole day most of the time. Sometimes I have to unplug the power to hard reset the monitors to solve the problem (not touching DP cables). After such a reboot the setup works like charm until the next day. The issue is random in nature, but definitely has something to do with initializing a DP session. Once initialize it works.

What are the revision numbers and 20 digit serial numbers off of those three U2415?

Sure. These are:

CN-008DXD-74261-48U-19VL

CN-008DXD-74261-48U-19HL

CN-008DXD-74261-48U-19PL

All are REV A00.