Video Jitter

aathan
aathan used Ask the Experts™
on
I'm wondering if others out there have seen problems similar to what I am experiencing with a new HP Pavilion 753n.  I have the machine's onboard video controller hooked up to an NEC MultiSync LCD 1525M monitor (analog) at 1024x768.

Every time the machine is working hard (e.g., during a CPU benchmark) or when the hard disk is being accessed, the video jitters.  Sometimes this is visible only in areas of fine detail (e.g., around text) and sometimes it is a broader effect over a larger portion of the display.

I have done an "auto adjust" on the LCD monitor several times, and have also used an alternative LCD 1525M.  I have not tried a different brand of monitor.

The problem is worse at 75hz and 70hz refresh; the video card is currently set at 60hz.

Do you think this is indicative of marginal video hardware, and that I should take advantage of warranty service on the unit?

Have others seen this type of problem and can you share your experiences?

Do more recent LCD monitors support faster refresh rates, and do you expect that a faster refresh will avoid this problem?

I went so far as to shield all of the drive & other internal cabling in the PC with tin foil grounded to the chasis!!! This improved the problem somewhat.

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Specialist 1
Commented:
Yes this is highly unusual that when you set the refresh rate higher and it gets worse.  It is indicative of marginal hardware.  I would definitely take advantage of the warranty service.  I have seen this type of problem before.  Sometimes it is due to a bad monitor cable, or a monitor cable that is not shielded properly.  Obviously to fix a bad/not shielded cable is to get a new one with proper shielding.

LCD monitors Depending on the model and size would depend on what you would set the refresh rate to.  LCD's run differently than regular CRT's or monitors.  Here is some information for you:
http://www.ges.com.sg/refresh.html


Commented:
I suspect you're using "shared memory" for VGA ( as this is onboard display) which is normally the case, with onboard display. You might need to increase the amount of shared memory in the BIOS ( CMOS )
 

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