To date I've been running a PC video card with svideo out to my HDTV. Picture is OK, however, real estate is limited due to maximum resolution supported and small fonts are unreadable. I just purchased a new video card with DVI out and am using a DVI to Component adapter to connect it to the TV as my only HDMI socket is already taken. I'm getting flickering images on the TV and it's possible to see the mouse moving across it, however, clearly the refresh rate is off. I've tried numerous combinations of standard & custom modes have not yet found one that gives me a steady picture. Can anyone help point me in the right direction. Equipment list as follows: -

TV - Sony KDF-55WF655
PC - Compaq Presario SR1113NX
Video Card - NVIDIA QUADRO NVS 55-PCI
Connecting Cable - Optoma BC-DICRXX02 DVI to Component RCA Cable

Any help much appreciated. Thanks in advance.

I suspect that your Graphics card supports VEGA along with DVI on its DVI-I connector which means that it would support RGB component with your cable but not YPrPB component which is what your TV interface is. Both versions of the component interface use the same set of RCA video cables but the two versions are incompatible.
If the specs for you card do not say the card supports HDTV-Out (the common term) used for YPrPb component then I think you are out of luck.

Thanks for the prompt & succinct supply - looks like a trip back to the store is in my future. Does anyone out there have a recommendation on a reasonably priced video card which does support HTDV out (YPrPB component) as described in walford's reply? Thanks again.

Major factors is selecting video cards are
1. Are you going to play a lot of games?
2. Do you plan on have an HDTV tuner card?
3. Do you have PCI 16E slot available or just an AGP slot?
4. Do you plan on using the PC to play HD-DVD or Blu-Ray DVDs?
5. What do you consider a resonable price?

1. Are you going to play a lot of games? - no - mainly browsing web & playing my DVD collection via MediaPortal (freeware tivo like application)
2. Do you plan on have an HDTV tuner card? - I have the Hayppage WinTV HVR-1600 NTSC/ATSC/QAM Combo card installed which can decode over the air HD broadcasts.
3. Do you have PCI 16E slot available or just an AGP slot? - PCI slot only (not sure if that is AGP), however, I know that I do not not have PCI Express slots.
4. Do you plan on using the PC to play HD-DVD or Blu-Ray DVDs? - No
5. What do you consider a resonable price? - Hoping to remain under $100. Much more and I may look to upgrade the whole system. I don't want to fall into the trap of buying really expensive add ons which would come as standard in a new PC - one which would probably cost less than the sum of the add ons.

Thanks again.

You might search at Newegg.com or tigerdirect.com.
A standard PCI slot card with HDTV-Out and with 128MB and the memory bandwidth to support HD stations using your 1600 digitak tuner appears to be hard to find.
I have a new Nvidia 8500GT chip card which meets all of your requirements including price but it uses a PCI-E slot.

you might want to try the htpc forum. i had the problem of flicking image, but with ati and dvi to hdmi cable. i found my problem was related to a setting in the ati control panel called "reduce dvi frequency".

What motherboard are you using and see if it has AGP.

Here's what I found on the Compaq / HP web site: -

Motherboard Description
Motherboard Manufacturer's name - MSI MS-6577 v4.0 GL6E
HP/Compaq name - Gamilia 2

Processors
Pentium 4 HT "Northwood"
Celeron "Prescott" and Northwood"
Socket 478

Chipset
845GV

Front Side Bus (FSB)
400/533 MHz

Memory
Two DDR DIMM (184-pin) sockets
Maximum memory: 1 GB
PC2700/PC2100

Audio
Down (on motherboard) AC97 (Realtek ALC658 chipset)

Graphics
Integrated

LAN
Realtek RTL8101L 10/100 Mbps Fast Ethernet Controller

Expansion Slots
Two PCI

I/O Ports
Rear
VGA
Two PS/2
One Parallel
One Serial
Four USB 2.0
One IEEE 1394
One RJ-45 LAN
Line in, Line out, Microphone in
Other
Two USB 2.0
One IEEE 1394
NOTE: Not all USB ports may be available externally for customer use; see model specifications

Feature Codes
G-graphics down (on motherboard)
L-LAN down (on motherboard)
E-1394 down (on motherboard)
6-6 speaker mode (Dolby 5.1)