Ampere PEX adn 1.8 v rails resistance value

[Burnedoutplacebo]

Working on a Zotac RTX 3070 with: PEX at 1v and 6.3 ohm., the 1.8v rail is at 5 ohms. mem is at 1.3v and 42 ohms and the Vcore is 0.7 ohms ( about 0.4 ohms above my background reading) at 0.75 v.

Question, are the PEX and 1.8v rails resistance too low? Have no video so trying to decide if dead core or something fixable. Dont have oscilloscope so playing with possible bios problem too.

Advice on resistance values for pex and 1.8v rails appreciated.

Thanks

[Burnedoutplacebo]

Re: Ampere PEX adn 1.8 v rails resistance value

Read resistance values from a working rtx 3070

1.8v = 2k ohm
5v = 4.9 k ohm
pex = 11 ohm

I think the PEX is okay but my project 3070 has a short on the 1.8v rail as it reads 5 ohms and a second short on the 5v rail where it reads 120 ohms.

Most likely i have a dead core causing the low 1.8v rail reading, not sure about the low 5 v rail reading but will continue to poke around on both rails to try to ID my short locations and verify if dead core.

[terror_alpha]

Re: Ampere PEX adn 1.8 v rails resistance value

from my experience, a low resistance 1.8v line while everything is fine means the core is dead. i don't think i've ever seen a card like that brought back. i binge watched a lot of GPU repair videos before started working on them myself.

i got a couple of dead gigajunk 3080ti here. all have the same problem. everything checks out except the 1.8V line. these are all parts cards now. all died recently

[Burnedoutplacebo]

Re: Ampere PEX adn 1.8 v rails resistance value

Thanks for the insight. Yep dead core. 1.8v. Short went away when removed the core. Was hoping was a bad solder pad but checked the pads on the core itself that connect to the 1.8v. Line and found 1 at the 6 ohm level. Only one but it was the cause.