identifying RTX 2080 Ti graphics card missing components

[newmaster]

Hey, I took a huge risk, buying a broken MSI GeForce RTX 2080 Ti Gaming X Trio


there are some PCIe decoupling caps missing, but also 2 components that I have been unable to identify yet. maybe somebody here can help me with it?


I attached a photo of a good board from the interwebs, marking the area of missing components and also a photo that marks the 2 mystery components.


one of them is most likely a resistor. it would be great if someone knows the value of it. otherwise the plan is to solder on a 20 turn potentiometer and try different values from high to low resistance. until it hopefully starts working.



but for the white component.. I have no idea what it could be. an inductor perhaps? or maybe just a LED? I can´t find better photos of this area of the card. maybe there are even some markings on the components. or somebody just has a dead card and can desolder and measure the marked parts?


also, if somebody has totally destroyed his or her card beyond the repair, I may be interested in buying a slice of that PCB

[jc101]

Hmm, that looks different to this YouTube of someone going through the hardware of one of those

Might be worth a look for generic pointers, there are some links to high res pictures of the PCB in the comments.

[wraper]

but for the white component.. I have no idea what it could be. an inductor perhaps? or maybe just a LED? I can´t find better photos of this area of the card.

Should be C0G type ceramic capacitor, thus should have low capacitance, most likely below 1nF considering it's size.

[Mr. Scram]

If only decoupling capacitors are missing it may be bad news. Few will cause the card to stop working.

[wraper]

PCIe decoupling caps missing,

Those are AC coupling capacitors, nothing to do with decoupling.

[newmaster]

PCIe decoupling caps missing,

Those are AC coupling capacitors, nothing to do with decoupling.

Yep, thanks for the correction.  I knew what they are for, but somehow consistently made that mistake in writing :/

Should be C0G type ceramic capacitor, thus should have low capacitance, most likely below 1nF considering it's size.

I desoldered a different cap from a visually similar part of the circuit. only way to measure this low capacity is my oscilloscope.  the cap seems more like something between 1-2pF. unfortunately the measuring setup itself measures about 15pF and changing with every movement of any wire. so it is impossible to get more precise with my setup.  I practiced with known capacitors to validate my method.
how important can it be to get the value exactly right?

[newmaster]

also, another missing resistor should be crossing PCI express pins A6 and A7 (correspondingly JTAG3 (TDI)  and JTAG4 (TDO) according to this page: https://pinouts.ru/Slots/pci_express_pinout.shtml )
I don´t know anything about JTAG, but since it is a standard protocol, then maybe somebody can lead me to a right direction.

attached a photo showing the location of the unknown resistor and  all the information I already know.