Hi,

I recently bought a Radeon 9800 series (256MB), but I'm having some confusing issues with it. After plugging in the power lead to it on my 300W PSU, when you pressed the power button on the computer, the pc would burst into life for a fraction of a second, and then die. If you removed the power lead from the Radeon, it powered up fine with the familiar "you need to connect your power lead" sign.

I figured a 300W PSU was too weak, so went and bought myself a 500W, but exactly the same thing happens.

Finally, after testing a few PSUs I had around, a 350W seems to work it; however my frame rate is exceptionally slow and 3D Mark results are way below what they should be.

I would ideally like to get the 500W PSU working...does anyone have any pointers?

My Machine Configuration is as follows:-

P4 3.4GHz @ 800FSB with 1MB Cache
1GHz dual channel DDR-3200
160GB HDD space
Radeon 9800 Series w 256MB RAM

Any help would be very gratefully received. I have done a google trawl and a few people complain about power issues - but nothing quite like this.

Lee

No ideas, anyone?

hey....

I would think it's a hardware issue, if a 500w psu doesn't work for anything less than a monster pc, you should think than there might be something wrong with the card itself.

Take it back to where ever you bought it and ask them for a replacement, first test it on a friend's pc just to make sure....

Good luck...

Go get yourself a real 500W power supply with good rating for 3.3V and 5V combined power.

It doesn't matter how much 12V power you have if 3.3V and 5v are wimppy. Every time you power up, your system logic required a minimum of 3.3V and 5V combined power to come up, under greater power demand the CPU and your graphic card will tap "extra" from 12V.

Typically, all power shared and originated from the same chopper transformer in your power supply, what power which get used up for 12V would not be available toward 3.3V and 5V.

In your case the 12V tapping actually cause in-sufficient left over 3.3V and 5V combined for power up, that was not "extra" your computer was tapping.

Aah right..I see. Thank you both for that!!

One more thing then - could you recommend a make/brand or model that you think would have a good rating? Most suppliers only tell you the wattage etc.

Thanks again for your assistance.