Need help for Gainward RTX 2080 Super repair

[gamaliux]

Hello everyone,

I have a Gainward RTX 2080 Super Phantom GHL graphics card.
Card does not work, these are the symptoms:
1. Fans spin 100% all the time;
2. If in bios main GPU is from PCIex, PC beeps 5 times;
3. I get no screen, and no BLACK screen. I mean monitor does not turn on at all, does not detect anything.

Testing I have done:
1. I have turned on PC with iGPU and checked card in device manager, it is found however it says error 43. I have tried to install drivers, nothing happens.
2. I have checked all the voltages, all are in range;
3. I have checked all pairs of PCIex lines with diode testing mode, all are fine;
4. I have tried to run Mods/Mats. However it says that PCIe device is not found.
5. I have tried to reflash bios. nVflash tool says that GPU is not found. I have desoldered both flash (dual bios) and using Beeprog2 I have flashed them with this .rom image (I have renamed it as .bin while flashing) https://www.techpowerup.com/vgabios/...80-8192-180918
However this did not helped either.
6. I have checked XTAL, I can see clock is generated.

One thing I have found that without heatsink and fans, GPU heats up till 100 degree in like 30 secs. Not sure if it should be like that, but with heatsink and GPU, bottom side of GPU is not hot at all, maybe that is normal.

Nothing helped at all. I'm really confused and do not have any more thoughts on how I could proceed here further.
I would very appreciate any help or tips on where to move forward I could get here.

Thank you!

[mon2]

Re: Need help for Gainward RTX 2080 Super repair

Confirm the small SMD components are present near the PCIe gold fingers.

Sometimes, a part can be damaged or go missing which will halt the detection of the PCIe adapter (any). Do inspect both sides of the PCB.

Mainly, there will be tons of dc-blocking caps that are 0402 in size. Each and every one should be present on the PCB if you have solder pads onboard.

Post pics if you can of the same area.

What is the history of this adapter ? It was working one day and stopped the next ? Was it dropped ? Any liquid damage ?

[gamaliux]

Re: Need help for Gainward RTX 2080 Super repair

Hello mon2!

Thank you for your reply!

I will inspect it deeper, maybe I have missed something, however I did not seen any problem with components.

I will post you pictures later today.

I have checked all PCIe diff lines on one side, each line had around 0.6V voltage drop, which indicated that side diff lines are good (also capacitors). However I absolutely forgot that there are pairs on the other side of PCB and one of the is REFCLK. And of course many other pins, however I'm not really familiar with other pins.
I will check this later today also.

I have bought it as defective. I do not know its history, that is also the problem. History may help to indicate the problem, however the person, from whom I bought this card, told me that he bought all PC and card was not working already.

No, there is no liquid damage, I have not seen any oxidation or anything else.

So, with all the other information I will come back later today. Thank you!

[ductranvinh]

Re: Need help for Gainward RTX 2080 Super repair

Need check:
Coil of 5v
Coil of 3.3v
Coil of 3.3v_F
Coil of 1.8v

[gamaliux]

Re: Need help for Gainward RTX 2080 Super repair

Hello Mon2,

Attaching photos as you asked.
I have checked each capacitor, there is continuity between pcie pins and caps, after caps I can see around 0.8V drop between GND. It seems that all pairs are ok.

Also you can see a photo where I have circled capacitors.
I can see that two of them may be soldered not originally, as I can see solder on full both capacitor sides and it is shiny. Also those caps shows 0.4ohm on them. I do not know if this is ok, but if these caps are realated to core 0.8V it is possible that it is ok, as there I can see 0.3ohm resistance on this voltage line.

[gamaliux]

Re: Need help for Gainward RTX 2080 Super repair

Hello ductranvinh@gmail.com,

Every coil has voltage. I have checked each of them.
However I have also checked resistances and it seems that 1.35V rail has only 3.3ohm, which I believe is too low. Card contains Samsung memory chips.

[ductranvinh]

Re: Need help for Gainward RTX 2080 Super repair

Hello ductranvinh@gmail.com,

Every coil has voltage. I have checked each of them.
However I have also checked resistances and it seems that 1.35V rail has only 3.3ohm, which I believe is too low. Card contains Samsung memory chips.

1.35v rail is voltage of vram ?!

[ductranvinh]

Re: Need help for Gainward RTX 2080 Super repair

If all the necessary and sufficient conditions for the graphics card to work but the main still does not detect it, it is highly likely that the gpu has a bad contact with the pcb and the wrong bios.

[gamaliux]

Re: Need help for Gainward RTX 2080 Super repair

Hello ductranvinh@gmail.com,

Yes, 1.35V of Vram. Voltage is 1.35V, however resistance low only around 3.3ohm.
I have tried to reflash bios, did not helped. Not sure if it was done 100% correctly, as nVflash does not detect GPU, so I desoldered both chips and reflashed them with image from techpowerup. I have wrote that in my first post.
Main GPU is currently the main suspect. However I do not know how to prove that it is faulty. I want to be sure, because I do not have tools to reball GPU, so the only thing I could do is to heat it up with flux. Nothing shows to GPU except for Vram low resistance, not sure if it has anything to do with GPU.

[ductranvinh]

Re: Need help for Gainward RTX 2080 Super repair

Hello ductranvinh@gmail.com,

Yes, 1.35V of Vram. Voltage is 1.35V, however resistance low only around 3.3ohm.
I have tried to reflash bios, did not helped. Not sure if it was done 100% correctly, as nVflash does not detect GPU, so I desoldered both chips and reflashed them with image from techpowerup. I have wrote that in my first post.
Main GPU is currently the main suspect. However I do not know how to prove that it is faulty. I want to be sure, because I do not have tools to reball GPU, so the only thing I could do is to heat it up with flux. Nothing shows to GPU except for Vram low resistance, not sure if it has anything to do with GPU.

The problem is that the main does not detect the card. Surely there must be a voltage line that is not working to cause this phenomenon. It is normal to apply 1.35v ram when the card works. It is not important to measure the impedance of the vram line and the gpu line because the impedance is very low. The purpose of impedance measurement is to determine short-circuit as long as the value does not fall below 1.0 ohm. The impedance of the gpu line is very very low (the value can be less than 0.01 ohm) and so is the vram line.

[gamaliux]

Re: Need help for Gainward RTX 2080 Super repair

Hello ductranvinh@gmail.com,

Thank you for your feedback.

I know that some voltage should be missing, however I can not find any.
I can see that every coil has voltage.
I can find 12V, 5V, 1.8V, PEX ~1V, 1.35V, 0.8V. Also 3.3V and 12V are coming from PCIe connector.
I'm becoming absolutely confused here.
Strangest thing is that Mods/Mats and nVflash does not detect card, however Windows detect it with an error (error43). I can disable and enable card, then Windows says no error found, but still nVflash does not respond to the card.
Also, I remember few cards where I got blue screens in windows, however this one does not show anything.

[gamaliux]

Re: Need help for Gainward RTX 2080 Super repair

I have made more measurements on graphics card.

I was wrong about 3.3ohm on Vram line, there is 20ohm as expected.

I have also checked PCIe Wake, CLKREQ and PEX_RST lines.

PEX_RST line has AND gate, however it is fine, output is correct.
Board PGOOD has also AND gate, it is fine also, output is correct.
Wake and CLKREQ are both active low. They both have only one 10k pull up resistor, no other circuit. As I turn on GPU, Wake signal is always high, however CLKREQ signal is always low. I do not know if it has to be like this, if anyone has any knowledge on this, please share it with me.