When cables go bad…

It’s 8:50 and your presentation is set to begin at 9:00.  You hook up your projector with a VGA cable and your beautiful PowerPoint presentation is all pink.  What can you do?  In this inaugural Holt AV Tech Tip, we will discuss the likely cause of this problem and how to fix it.

This month’s tip concerns a problem that everyone who is called upon to make numerous computer based presentations will eventually come across.  Although it is a simple problem to fix, it can ruin a well crafted PowerPoint slide show.  This problem is the dreaded “Pink Screen” effect.  This can occur at any time during a presentation and, due to Murphy’s Law, often shows up right in the middle of that really crucial sales pitch.  First, we’ll see what this looks like and then discuss what is wrong and how to fix it.

Normal imageThis is an example of the original output from the computer and what is projected on the screen.


In this image, notice that all of the colors, red, green, and blue, are visible and the image looks normal.




bad cable example - pink

Signs of a cable problem

However, when something goes bad the “Pink Screen” can be seen.


Here we see that the image has a pink cast and some areas are too dark to see at all.




bad cable example - bluebad cable example - yellowThis problem can also show up as a blue screen and a yellow screen as shown here.




The cable fix

These types of presentation disasters are often of the result of the same basic problem.  The discolored images are classic examples of what you might see if there is a bad cable connecting a laptop to a projector.  The root cause of the discoloration is a broken wire in the cable (often called the VGA cable) and one of the main colors that make up the images, red, blue and green, is missing.  In the case of the pink screen, the wire carrying the green signal is broken.  With the blue colored image, it is the red signal and in the yellow image it is the blue signal.

Many customers assume that their projector is failing when this kind of discoloration occurs, but more often than not it is just as simple as a bad cable.  The very first thing we as technicians check when we are called to help with a discoloration problem is the cabling.  In the majority of cases, the problem is solved in less than 5 minutes.

For all of you mobile presenters out there, we recommend carrying a spare cable in your projector case.  Cables take a lot of abuse during mobile use and they will fail eventually.  Six foot VGA cables are lightweight, inexpensive and invaluable to both the mobile presenters and conference room technicians.

That’s it for this month’s tech tip.  As always, if you have a technical question about any AV related subject, please email us at techtips@holtav.com.  If your question is chosen for the monthly column we’ll send you a free gift!