Hd 4870, PC won't boot properly

[Marioponda]

Hi,

today i recived a used Sapphire HD4870 512mb gddr5.
Problem is, i followed the standard procedure for upgrading a PSU, so i disintalled the previus Nvidia Drivers, i turned down PC, unplugged the power cable, than removed the old card, plugged the new one with all the 2 6pin PSU cable connected, correctly inserted the card in the PCI-e slot and re-povered the pc. -standard procedure-

At startup, the screen tooked several seconds (more than usual) to "wake up" from standby, and displayed just random vertical and orizzontal white lines on a black background for like 10 seconds, after that the screen went back to "standby mode", while the pc was still running.
No other response from the screen.

Note that no one of the red led on the GPU is lit, and that should be a good sign, is it?

PC specs:
-p5k motherboard
-550w PSU (rasurbo), with 12v +19A and +18A
-Intel Core2 Quad CPU
-4 GB ram

I tryed to:
-take away some RAM pack - no difference
-disconnect one of the 2 hard drive - no difference
-resetting the mobo BIOS taking away for some seconds the mobo battery - no difference

The PC work fine with the old "windows default" GPU (but have no integrated one)


PS: (I made like 2 hours of hardcore-using of the search function in this and other forums, but i could not find a proper solution)

Thanks in advance for your help!
Mario

 

[COLGeek]

I suspect that your PSU is not strong enough to power the HD4870. What make/model of GPU were you using before the HD4870?

 

[Marioponda]

I used a NFX Nvidia 8800gt "Alpha Dog edition", that should need like 106-110W, so not so many less than a HD4870...

Anyway i checked, i had plugged the 6 pin and 2 4pin (molex) -with the adapter, both coming from the central psu- and with 2 lines 12v 18Amps, it should be like 400W or so... (but i'm no expert about this)

 

[COLGeek]

Not all PSUs are created equally, regardless of what is on the label of the PSU itself. I am not familiar with the brand of yours, but you are describing a typical power shortage (assuming that the HD4870 works).

 

[Marioponda]

Not all PSUs are created equally, regardless of what is on the label of the PSU itself. I am not familiar with the brand of yours, but you are describing a typical power shortage (assuming that the HD4870 works).

Thanks, i'll ask a friend of mine to lend me a more sutained PSU and try with it...if u tell me those are the sign of a power shortage, i'll take it for good
...all this hoping that the hd4870 works fine, that's not assured...

 

[COLGeek]

Try the HD4870 in your friend's rig before swapping out his PSU, to confirm it is good.

 

[Marioponda]

Not all PSUs are created equally, regardless of what is on the label of the PSU itself. I am not familiar with the brand of yours, but you are describing a typical power shortage (assuming that the HD4870 works).

Interesting new data!
If i unplug (from the psu and/or from the motherboard) the Hard Drive c:/ (booting &system hard drive), the screen turn on, still with white lines on black background, but under the white line i can read (in a dos-style type) something like
"reboot and insert a Booting ---- or insert a Booting device and press a key"

If than i plug in the c:/ disc, the disc start, but it's not recognized like a "booting device" and simply the text above is repeated, over and over.

So, i can kinda exclude the lack of power...but i don't know if that's a bad or a good thing...

 

[COLGeek]

It still sounds like an under-powered PSU.

Try this, disconnect everything but the HD4870 and power the system on. Does the BIOS display properly?

 

[Marioponda]

It still sounds like an under-powered PSU.

Try this, disconnect everything but the HD4870 and power the system on. Does the BIOS display properly?

Same as before, it displays the white stripes (sadly not the musical band) with underneath the confused and half-pixelated " insert boot device" lines...

BUT i inserted my "default microsoft" GPU in the secondary pci-e slot, and set the bios to run that before, so now i can use windows with the HD4870 inserted and powered.
The system kinda recognized the GPU, and i even manually installed the CCC and the "4800 series driver", but still, if i plug the screen on the hd4870, the screen goes into "standby" mode...


PS: i'm so thankfull for your help and your time

 

[Marioponda]

ps: don't know exactly how, probably plugging the screen in the hd4870 after the pc started with the standard gpu as default, on the screen i saw a windows-like message sayng that the pc are going to restart due to some video-tdr-something problem...it doesn't lasted long and was very confused by some grey-white lines all across the screen...

But, nonetheless, at least the HD4870 displayed something...

 

[COLGeek]

Seems like the HD4870 is the problem then. Do you have access to another system that you could install into to see if it works there?

 

[Marioponda]

Seems like the HD4870 is the problem then. Do you have access to another system that you could install into to see if it works there?

Now, if i launch the pc with the screen plugged in the HD4870, the pc start, white lines for few seconds, screen go in standby, but THAN, after some time, i see a light-blue screen (not screen of death) that says: "computer is about to restart due to some .... problems... VIDEO_TDR_FAILURE atikmpag.sys"
There is a % count, when it arrives at 100%, the computer restart, and this cycle over and over again.

PS: the light-blue screen is all messy, with a lot of misalligned things and grey lines all across.