XFX Speedster MERC319 Radeon RX 6800XT +3.3V short, please help!

[bowhite]

Hey so I got a used GPU from FB marketplace. When I plugged it in the LEDs light up, but no fans spin.

Cuz it was used and I got a refund from the seller who didn't want the non-functional card back I'm trying to see if I can fix it.

My multimeter shows a short on the +3.3V PCIE rail, what do I do now?

I haven't been able to find any board schematics, and most troubleshooting videos seem to stop once a short is detected.

Have included pics for reference, would love any help or advice on getting this card working again, but also not a huge loss if this is the end of the road.

Thanks!!

PXL_20250621_234311921.RAW-01.COVER.jpg PXL_20250621_234209936.RAW-01.COVER.jpg

[strange13930]

25 minutes ago, bowhite said:

Hey so I got a used GPU from FB marketplace. When I plugged it in the LEDs light up, but no fans spin.

Cuz it was used and I got a refund from the seller who didn't want the non-functional card back I'm trying to see if I can fix it.

My multimeter shows a short on the +3.3V PCIE rail, what do I do now?

I haven't been able to find any board schematics, and most troubleshooting videos seem to stop once a short is detected.

Have included pics for reference, would love any help or advice on getting this card working again, but also not a huge loss if this is the end of the road.

Thanks!!

PXL_20250621_234311921.RAW-01.COVER.jpg 8.48 MB · 1 download PXL_20250621_234209936.RAW-01.COVER.jpg 7.99 MB · 1 download

where is the short at on the +3.3v pcie rail?

[bowhite]

unsure, that's what I'm hoping I can get help figuring out.

right now my multimeter beeps when probing the +3.3V 4 pads in on the front side.

[strange13930]

22 minutes ago, bowhite said:

unsure, that's what I'm hoping I can get help figuring out.

right now my multimeter beeps when probing the +3.3V 4 pads in on the front side.

do you happen to have a digital thermal camera? where ever the short is it should heat up when powered on.

[bowhite]

thats a great idea, i'll try that tomorrow

[bowhite]

On 6/21/2025 at 6:56 PM, strange13930 said:

do you happen to have a digital thermal camera? where ever the short is it should heat up when powered on.

okay so i think this is the hot spot, any advice on what I can do to fix it?

[strange13930]

56 minutes ago, bowhite said:

okay so i think this is the hot spot, any advice on what I can do to fix it?

first we have to figure out what part that is and a replacement for it, I'll do some research

[bowhite]

you're the GOAT

[-rascal-]

The thermal image overlay may be slightly offset.

It looks like it's the IC labelled as U304.

 

You can take a digital-multi-meter and measure across the capacitor and resistor, and see if either of them is shorted / behaving abnormally.

[strange13930]

20 hours ago, bowhite said:

you're the GOAT

are there any numbers or letters on U304?

[bowhite]

@ -rascal- I dont really know what i should be doing with the multimeter to see if they're behaving abnormally. 

its also so small that its really hard to be precise with the multimeter probes.

Here's a high res pic, looks like it says "3070 Ti 12i AFXT" but not super sure if thats 100% correct.

Is the IC the prospective defective component, not one of the resistors/capacitors in this area?

 

[strange13930]

On 7/5/2025 at 2:02 PM, bowhite said:

@ -rascal- I dont really know what i should be doing with the multimeter to see if they're behaving abnormally. 

its also so small that its really hard to be precise with the multimeter probes.

Here's a high res pic, looks like it says "3070 Ti 12i AFXT" but not super sure if thats 100% correct.

Is the IC the prospective defective component, not one of the resistors/capacitors in this area?

 

i haven't been able to find anything on it, you could try contacting xfx to see if they can either send you one or show you where to by it