IBM Thinkpad Oddity

Silhyboy - Sep 23, 2010 at 08:44 AM
 Tim - Oct 24, 2010 at 05:44 PM

Here's a head scratch-er for ya'll... IBM Thinkpad T-series plugging into an AV system in a corporate setting using a VGA cable with the 3.5mm audio connector attached. When the audio cable is plugged into the laptop, there is nothing wrong with anything, if the audio cable is disconnected, a distinct chirp (simplest way to describe it) starts coming from the audio system.

Now we made sure that the video cable was terminated correctly on both ends, the audio cable was correctly terminated as well. We isolated the audio input on the AV system so that it was only that input open with the 3.5mm cable on the computer side dangling but on the AV rack side terminated. We tried on a different system completely and same effect.

Just wondering if the new IBM laptops are having any grounding issues with the on-board graphics and audio chips? It's the only answer that comes to my mind.

1 reply

I was told that its a grounding issue.... because the power cable has only 2 prongs, not 3, so it doesn't have the grounding wire. They said to try and plug into an outlet, not a power bar, or try a noise cancelling powerbar.
Good luck