Tech Advisor
hed: Video vexation
dek: also, beware of vibrating CDs and carriers already present.
by Stephen J. Bigelow
Q: I just changed my video adapter, and now my DVD movies won't play. The new video card works fine otherwise. Is the card bad, or just incompatible?
A: Chances are that your new video card is neither defective nor incompatible. In many cases, the problem is that the links between your video and DVD drivers have been "broken" during the new video card's installation.
When a new video card is installed, it changes entries in the Registry that associate MPEG playback with video-card drivers. The new video card's MPEG drivers may not be fully DVD-compliant, and since they probably took precedence over the MPEG drivers of the DVD system, this may be your problem.
Try reinstalling the video card from scratch (use the latest drivers downloaded from the manufacturer's Web site), then reinstall the DVD drivers and software applets. This should reinstall the proper DVD MPEG-ready drivers and correct the problem.
Q:I've got a Plextor CD-ROM drive that makes a lot of noise when it spins up, but this doesn't happen with every disc. I've seen it happen with a few commercial CDs, and a lot of CD-R discs. Any ideas?
A: This is classic problem that's often encountered with faster CD-ROM, CD-R, and CD-RW drives. Just as car tires must be balanced to spin properly at high speeds, unbalanced discs may cause excessive drive vibration.
As the rotational speed of today's CD-type drives continues to increase, a disc's balance becomes more important--the improper placement of a label (even too much ink on one side of the disc) can offset the disc's balance enough for the drive to vibrate at high speeds. The vibration may also resonate in the PC case, causing the sound to seem even louder.
The solution to this type of problem is to check each vibrating disc to see that it's even. Equally important is removing any labels or foreign matter that might offset the disc's balance. If you installed the Plextor Manager software that accompanied your drive, you might be able to use that to slow your drive to a lower level and reduce vibrations.
Q:When I try to use my modem, I get an error that says "Already Online--Carrier Already Present." Where does this message come from, and is there anything I can do to fix it?
A:There are several conditions that may cause this type of trouble. First, the modem may already be online when you start a communications package. Make sure that you're only using one communications program at any given time.
Second, the serial CD (Carrier Detect) signal is set to "Always on," using a command code such as "AT&C0." Reconfigure the modem so that the CD signal is not always on.
Finally, you may hang up the modem without signing off from the host system. Always terminate your online session and verify that the modem hangs up properly. In most cases, you can prevent this problem by using the following command string:
AT&C1&D2&W
This command ensures that the CD signal is on only when the modem makes a connection (&C1). The &D2 command causes the modem to hang up when the serial DTR signal turns off. The &W command tells the modem to save its settings in the modem's NVRAM.
Click Start, Settings, Control Panel, and double-click the Modems icon. Highlight the modem in the General tab and click the Properties button. Click the Connection tab, and click the Advanced button.
You can add the command string to the modem's properties in the Extra Settings entry of the Advanced Connection Settings dialog. Remember to save your changes and reboot the system if necessary so that your changes can take effect.
