RTX3070 not detected/ no display - has all voltages and pex reset question

[woody-009]

Hi Everyone

Ive got an RTX 3070 Gigabyte vision oc that i picked up from a miner who said one day it just stopped working. The card isnt detected and has no display, the core gets very warm within 30 seconds and i have all voltages on the inductors
12v, 5V, 1.8V, Vcore 0.7v mem 1.35v and pex 0.9v
My resistances are 5v 0.9k ohm, 1.8v 30 ohm, Pex 6.6 ohm and the rest are normal
any ideas besides dead core?

With the pex reset B11 pin am i supposed to get 3.3v supplied from the motherboard? at the U501 logic gate i am not getting any voltage from the input pins 1 and 2. i have 1.8 vcc and ground but no supply from the motherboard. Should this be a 3.3v signal to this gate and therefore a 3.3v signal leaving the gate?
Here is a link to the u501 datasheet
https://html.alldatasheet.com/html-p...74LVC1G08.html

I will also include a screen shot of the diagram for the U501. the board doesnt have the U503 or R514, but does have the r535 but i dont get 3.3 v on either side of it and i have direct continuity between pin A11 and pins 1,2 on the logic gate

This is my first 3000 series card so still learning. I do have a gigabyte 3090 in my pc but im not massively keen on pulling it apart to compare it unless i have to.

Thanks, Kurt

[LupenWonse]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

PEX_RST* is active low. Meaning that for the card to work you need a high signal. (When it is low RESET is active). I believe high signal is 1.8V for this case but I may be wrong.


Since you have no input on U501 and U503 is before that I would check U503.
Is 3.3V present on pin 1 and 2?
If so, you are getting correct RST from PCI but there is a issue with logic gates. If not you are not getting out of reset from the PCI but why and how that would happen is beyond my knowledge

[woody-009]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

Thanks for the reply

I thought that was how the pex rst worked so i may be onto something?

The card doesnt have the u 503 installed and doesnt appear to have been ripped off but does have the 0.05 ohm resistor installed that bypasses the u503, but i will check the u503 pads for 3.3v anyways (i think its meant to be 3.3v, it is on my rx580s not sure about 3000 series) the 0.05 ohm resistor reads 0.1 on my meter which is basically as low as it goes so i assume its ok, i dont have any voltage on either side of it anyways. i will try to probe the A11 pin for supply voltage when i have a mining card riser free as its a bit tricky to do on my test motherboard

[woody-009]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

so ive tested the card in a mining riser and i get 0v on pin A11 pex rst coming from the motherboard. Is there anything that is sent from the graphics card to tell the motherboard to switch the voltage on to this pin? i also have 4 ohms to ground on this A11 pin which probably isnt normal

[LupenWonse]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

I am really a newbie so somebody let me know if I am writing non-sense.
That being said since this pin is connected to the logic gate could it be possible that the logic gate has failed? Otherwise you should be reading a higher resistance on the pin. Maybe remove the logic gate and check again?
The line then should be open and measurement on the riser should be 3.3V

[DynaxSC]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

Check the resistance you have on A11 if it is in ohms level, whatever is connected to it has a short, can be CPU directly or over a logic gate (You have most probably this logic gate, which is good, as it might have protected the GPU). And yes, both can get shorted, eg due to an electrostatic discharge. If there is a short desolder the logic gate (with hotair gun or two irons and somewhat more tin to cover all the legs) and measure again, also the output going to the GPU. Instead of resistance, you can also measure in diode mode, if voltage = zero, then you have a short. And I wouldn't power the card before replacing the logic gate, nowbody can predict what this may cause, further demage is possible.

[woody-009]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

Thanks for that. I had a look last night and the logic gate is shorted to ground. So I've ordered some and will play the waiting game. I tested my good rtx3060ti Asus dual fan card and A11 has no resistance to ground whereas the 3070 with the ground pin of the logic gate desoldered still has around 300 ohms so hopefully it hasn't fried the GPU. Time will tell I suppose

[woody-009]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

I got the replacement logic gate and repaired the card last night and it works perfectly. So it seems those voltages and resistances are fairly normal. Thanks everyone for the help

[furygrim]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

Hi I've got similar problem apart from PEX is present I got 1.8v on pin 4&5 u501 then 3.3v on pins 1&2

All other voltages are present as well and ohms seems to be fine on all inductors.

GPU isn't being detected under windows, fans do spin but RGB isn't working.

GPU MSI Rtx 3070 gaming trio X

Thanks for help

[hallmark1730]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

Hello, I have a 3090 in a similar situation. The and logic gate with the code u811(74VHC1G08) is vin 1.8 v, but where is the problem with the 1st 2nd and 3rd legs grounding(multimeter is beeping all legs). 1st and 2nd legs 3.3 volts is required normally.

[JHOMBY]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

I got the replacement logic gate and repaired the card last night and it works perfectly. So it seems those voltages and resistances are fairly normal. Thanks everyone for the help

hello friend, almost the same thing happens to me as you, in my case leg 1 and 2 of the logic gate give me 1.4v and leg 4 0v, the most probable thing is that the logic gate is damaged, I would like you to tell me what they are the voltages of legs 1,2 and 4 already with the graph working.

thank you so much

[Burnedoutplacebo]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

hello friend, almost the same thing happens to me as you, in my case leg 1 and 2 of the logic gate give me 1.4v and leg 4 0v, the most probable thing is that the logic gate is damaged, I would like you to tell me what they are the voltages of legs 1,2 and 4 already with the graph working.

thank you so much

On my 3070 I have

pin 1 = 3.3
pin 2 = 3.3
pin 3 = gnd
pin 4 = 1.8
pin 5 = 1.8

That being said, my card is not working but my fault is likely elsewhere.

I would like to know the normal resistance value on the 1.8 v rail if anyone knows. Thanks

[JHOMBY]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

On my 3070 I have

pin 1 = 3.3
pin 2 = 3.3
pin 3 = gnd
pin 4 = 1.8
pin 5 = 1.8

That being said, my card is not working but my fault is likely elsewhere.

I would like to know the normal resistance value on the 1.8 v rail if anyone knows. Thanks

thanks friend for giving me that information

[JHOMBY]

Re: RTX3070 not detected/ no display - has all voltages and pex reset question

I got the replacement logic gate and repaired the card last night and it works perfectly. So it seems those voltages and resistances are fairly normal. Thanks everyone for the help

Friend, could you tell me where you bought the logic gate?