PNY 1080TI repair

[gtrak]

Hi all, I'm new to this forum, but I've taken the plunge and bought myself a broken 1080TI to attempt to repair, despite my immediate regrets.

What I've noticed so far is it's clearly been taken apart before.  The back of the board seems to have some oxidation or evidence of a spill. I thought it's possible someone tried to bake it?

When turned on, the fan does spin, but no display.  The main chip does get warm.

On the front, I noticed a couple of caps towards the right were sitting unevenly, on closer inspection they were damaged and I was able to easily remove them by pulling lightly.

I think I need to clean the board and replace the caps, at least. What should I check next?  I know my way around a multi-meter, and have watched some youtube videos on the topic, but am feeling like I'm out of my depth.

How bad is this?

[gtrak]

I've noticed a couple more things.  The dirty stuff comes off with isopropyl, kind of black on the napkin. I'm not sure what it could be.

There's some physical damage to the top right corner on the back, not sure how critical that is.

I've attached a picture of the reference PCB to compare.

[gtrak]

I found one more issue that seems related to the power caps.  On the back, there is a chip marked 'up9511p', which is some sort of power controller.  It is physically damaged with a chunk having been taken out of the exterior IC package somehow.

It is referenced in this document https://xdevs.com/guide/pascal_oc/ as a way to add more voltage.

I think it's likely that this is the smoking gun, and I should find a new one and a heatgun?

[TheMG]

What I think: card probably had some sort of issue and someone tossed it into e-waste, someone then fished it out of the e-waste bin and put it up for sale. The damage to some of the components looks like the type of damage that would occur from a circuit board being tossed in a bin.

I guess you could replace the missing/damaged capacitors and test for proper voltages at the output of the various on-board voltage regulators, beyond that, I'm really not sure, as you're not likely to find schematics or diagnostic tools for a video card. Reflowing with a heat gun is likely to do more harm than good as you don't even know at this point whether there is a suspected BGA fault with the card.

And don't ever power up the card without a heat sink installed. At best, the card will detect the sudden rise in core temperature and promptly shut down, at worst you'll fry the GPU. The bare GPU die without a heatsink will get very hot extremely fast.

[gtrak]

Thanks man, that makes a lot of sense.

I'm still going to attempt a few things.

I'm having a hard time searching for a missing transistor, I think it's a transistor (just looking for more stuff that might have gone wrong in that power delivery area before I begin soldering and break out the multimeter). It's not clear to me if it was physically pulled off or blew up, but the solder pads look like something used to be there, and it's there on the reference image. They're marked 7kj0A in the Q512 position.

[testpoint1]

BGA desoldering is not easy, you may practise more than 1 year then can rework the IC.

[gtrak]

oh come on :-).  I'm not doing the main chip and reballing stuff, just a smaller one off to the side.  I think up9511p is not actually BGA, but just surface mount with a big ground square in the middle?

[DaJMasta]

Yeah, probably QFN.  Definitely look up the part and look for a demo circuit, and try to replace the passives that are missing next to the chip.  While it is damage, that damage is not characteristic of an IC failure, and with the missing passives near it, I think is probably from just an impact.  There's a good chance the chip is fine, but the passives missing and breaking the circuit aren't.

As for the other transistor - it's hard for me to say either way from the pics, but maybe you can find a pic of the board somewhere else to see if it's populated on other boards.  There have probably been revisions and maybe some have it, but if you can find another board with the same combination of transistors, maybe it isn't needed.  Unless the soldering was kind of crap, I wouldn't expect a SOT-23 to rip off without either leaving bits of itself or tearing off pads.