ELP!!!!!! Plug in New AGP graphics card, CPU cannot boot, no output at VGA.

[veto]

Hi guys, this is my first time posting here and I hope someone can help me.

Recently, I just wana watch Youtube HD, and I purchase a new graphic card, but after I plug in, CPU simply cannot boot. No signal at VGA output.

My com specs:
HP Workstation XW4100
Processor: 3.0GHz Pentium 4 Processor
RAM: 3GB RAM
Motherboard: HP 0868h (it has an 8x AGP)
Harddisk: 160Gb Serial ATA / 7200 HDD
OS: Windows XP Professional
Old Graphic Card: Nvidia Quadro4 380XGL (AGP)
New Graphic Card to be installed: Sapphire ATI Radeon HD 3450 512MB (AGP)

What I did:
1) 1) After I purchased the new graphic card (Sapphire ATI Radeon HD 3450 512MB AGP ), I plug in, switched on, fan on, motherboard LED on, Graphic card LED on, but CPU cannot boot, no beep sound, totally no output from the VGA, monitor totally nothing, and wait forever. I plug in the external power from PSU to the Graphic card, also nothing.
2) Ah, I think maybe the graphic card is power hungry and PSU is not delivering enough power. I then purchased a 500W PSU (more than enough), I plug everything in, same, no output, CPU cannot boot!! Really wasted my money on the PSU.
3) The LED of the Graphic card is lit up, which means yes, PSU is delivering the required voltage to the Graphics.
3) I take out all the RAM, and power on, yes, CPU has beep beep sound. Motherboard is ok.
4) I put back my old graphic cards in (Nvidia Quadro4 380XGL), everything becomes normal. I can start up to windows.
5) Tried the new graphic card on other system. It is working fine.
I am at wits ends. I totally don’t know what to do now. If I bring the whole bulky CPU to computer repair shop, the cab fare alone is going to cost me a bomb. Worse, if the outcome of the diagnosis is simply “oh, incompatible”, I m just wasting my trip.


I did thought of changing a new completely new CPU since AGP is already extinct, but I just simply want to watch youtube HD 1080p video only, I am not into gaming or any professional stuffs. That’s all


I sincerely sincerely hope somebody can advise me what to do… really appreciated.

 

[unksol]

Honestly it's hard to say. You entire system is ancient and needs a rebuild, but the gpu could just be bad, it's also ancient. I assume you got it off Ebay?

 

[Shadow_07]

The answer could be that its just incompatible, But if you want something you can try, If your motherboard has built in graphics, With the computer off Unplug the AGP card, now switch it on and Go to the bios using the on-board graphics and disable the on-board Video display, Now set the primary slot to AGP, save, and listen for beep on restart, switch it off and plug the new card and see what happens when you start it again.

 

[navalweaponsofficer]

Some old MB have compatibility issues with newer hardware. There is a BIOS update for that computer it may fix your problem. Make sure this is your computer check the latest BOIS version and compare it to the version on your old MB you will need to install the old AGP card to read your BIOS version. http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?lang=en&cc=us&prodTypeId=12454&prodSeriesId=314651&swItem=wk-24553-1&prodNameId=314653&swEnvOID=1093&swLang=13&taskId=135&mode=4&idx=0
If a BOIS update does not fix the problem then it is just incompatible with your computer. Then try an NVIDIA card or get a new computer.