[aSpartan111]

Hello All,

Thank you for all your inputs !

Yeah, i saw Weblacky's post about the replacement service.
And like @Weblacky said it wouldn't be very economical to me.

Noneless i've read that thread and found some precious info, but i still have some questions.
Do DS1780 always tends to short the 2-wire bus when they fail ?
And did you have any case where a chip falsely reported only one of it's input voltage and without shorting the bus (the datasheet lists 5 different voltage inputs possible) ?
I know considering electronic chips malfunctions everything is possible, but the last possibility seems unintuitive to me.

I can easily order (and will, eventually) the part here but it's still 6.5€/pcs (with 5pcs min. order).

Also thank you @jwhat for the link you provided, i flew over the thread (i will read it carefully when i'm finished with this answer).
And apparently there is 3 locations for the DS1780 on the 2U_Interface. ( I already had the two obvious in G7G5 & H5G5 but to the sneaky in N4K4).
Now i will have to find which chip is responsible for the PCI 5V voltage, and i think it will be easier to me to do the measurements on my working brick (as it dosn't power itself off).
Once I have all 5V measured on the working one it will be quicker to measure on the "dead" one.

And considering my soldering skills, i have no fear.
I did some tsop28 de/re-soldering (for BIOS flashing with a TL866) on my OG xbox without low-melt solder, flux or hot-air station.
And since then I've treated myself with some equipments and consumables (all sort of flux, kapton tape, thin solder wire, solder paste, etc).
So far i have no experience with BGA and very few with QFN :/

Thank you all for your precious answers, reading me and your future answers.
I will keep you informed of my findings.