Connecting your Microsoft Surface Pro 3 to a Dell Monitor via Display Port

This article is a little off topic, but I can now provide a solution to a technical issue that I have been having and hopefully, it will save someone else out there the hassles that I have been having.

The problem is that when connecting my Surface Pro 3’s Mini Display Port (MiniDP) connection to the Display Port (DP) connection of my 27″ Dell Monitor (U2713HM), the monitor would refuse to power up if the computer was already on.

The solution is simple you say: “Turn on the Monitor and then turn on the computer”.

Yeah I know, but I am also using a smart power board which only provides mains power to the monitor (and other peripherals) after the computer is on and drawing power. Because I am using this board (and saving on standby energy costs), I can’t turn on the monitor first.

I was able to get everything working as desired using a long Display Port cable (that was included with a different Dell monitor a while back) and a Delock MiniDP to DP adaptor I bought from Optiwire on eBay.

However, I wanted to have a single cable without an adaptor and so tried twice to purchase MiniDP to DP cables, once from another eBay seller and once from Optiwire. Both times the cable, which says it should work for Mac and PC failed to work. The same issue, the Dell Monitor fails to power up and has to be left off and disconnected for a few minutes, before it will work again.

Jeff from Optiwire (http://www.optiwire.ie/ Note: site will be live soon) was very helpful and together we did some research on the interwebs and found a number of forum and discussion posts where other users were having similar issues when connecting Dell Monitors via Display Port.

Now, we never found anything from Dell admitting that they had an issue, but it seems that the problem is to do with pin 20 (DP_PWR) on the Display Port connection. If it is connected, and has power on it, some Dell Monitors will fail to power up.

As I wanted to have a spare Display Port cable and adaptor, I ordered another short cable and adaptor for use with my Surface Pro 3. When they arrived they failed to work again.

So, with a quick bit of troubleshooting, I identified that the old cable worked with either of the adaptors, but the new cable did not. In disgust, I got out the trusty multimeter and started checking the pin 20 connections.

The result is that the old cable does not have pin 20 connected and that is why it worked. The new cable and adaptors do have pin 20 connected. And so did the MiniDP to DP cables.

So my solution: I popped open the case on one of the adaptors, located the circuit board track for pin 20 and scratched through it. Now the modified adaptor works with the new short Display Port cable.

So, if you are having trouble with a Dell monitor using a Display Port connection, either find a cable that does not have pin 20 connected, or modify the cable (or adaptor) to disconnect pin 20.

Problem solved.

David

This article was originally posted on http://www.winthropdc.com/blog.