I have a Voodoo 4 4500 AGP card that is working intermittently on two different systems that worked fine with other AGP cards.

Sometimes I only get a black screen and no video or motherboard POST.
Sometimes I only get a Video and motherboard POST then blackness.
If the video and motherboard post, I can get into the BIOS settings.  

When I do see a video POST, every other letter is flashing on and off.
Also, when motherboard POSTING or in the BIOS, I see thin vertical lines on the screen.

So then I try to update the V4 4500 BIOS.  I install a nVidia FX5500 PCI card and boot with that card as primary, then I load a DOS startup disk and then run then flash utility with BIOS 1.15.  So the Flash program begins to setup and I get a message: Unable to identify board.  The flash program just stays at this message screen.

Ok, so now I ran PCI.exe that Hank recommends to figure out if your card is nuked.  

"Boot to DOS, then execute PCI.EXE. You should see several devices, the ones you are looking for are 121Ah (3dfx). If you see the device then your card is alive and just the BIOS is nuked. If you do not see the 3DFX signature, say good bye to the card."  Hank Semenec

I see: 121Ah [Unassigned]  0001h Video Multimedia

Is the card dead?

>So the Flash program begins to setup and I get a message: Unable to identify board

This is most likely because of a wrong version of the flash prog.
As long as PCI-ID 121Ah is found ( as it IS in your case ) the card is still alive and can be reflashed.
I can check for the right version of the flash prog when I am back home and let you know.

From what you say, I think you have a damaged card (bad memory or something else, but a hardware problem anyway).

:)  thanks for the helpful responses.

Here's a screenshot when running PCI.EXE:

http://i298.photobucket.com/albums/mm241/razr_x/th_11-13-08_1154.jpg



Here's the screenshot when I get the error that the Flash program is unable to identify the board:

http://i298.photobucket.com/albums/mm241/razr_x/th_11-13-08_1147.jpg


I am using the same floppy disk (and files) that I used to flash my V5MAC to PC BIOS, except I am using 45k115a.rom

I downloaded all the files from: http://3dfxbios.stantoworld.co.uk/

Files on the floppy:
45k115a.rom
DOS4GW.EXE
DUMPBIOS.EXE
FLASH.EXE

I will try redownloading the DOS4GW.EXE, DUMPBIOS.EXE and FLASH.EXE again, in case the files went corrupt.  

-EDIT- I redownloaded the files on the floppy from Stanto's website, but I still get the same error.

I tried the flash program on 3dfxzone.it, and still no luck.

I am trying two flash programs both version 2.14 but one of them gives me a little more info on the "unable to identify board" message.  the next line states:  "ERROR:  Unknown flash EEPROM manufacturer.  Man. ID: 00h, Dev. ID: 00h"