Asus GTX 970 Turbo No Picture

[krsta]

So, where to start.

I bought EVGA GTX 970 and Asus GTX 970 Turbo for 30 Euros total (warranty stickers were untouched).

The EVGA one has a short on 12V external power rail on high side mosfet of the Vcore, ordered low, high side ones and mosfet driver just in case because it takes 20-30 days for it to come from China. When they arrive ill post the result.


The Asus one is pain in the ass.

https://imgur.com/kjHzBi3
https://imgur.com/G29eh7n

Before disassembling the card i measured resistances and all that i could reach.

12V PCIe 8.8k Ohm
3.3V PCIe 860 Ohm
Vcore 9 Ohm
Vmem 29 Ohm(Samsung)

I noticed the broken cap with pad torn of on pcie dataline. Because my solder mask did not arrive yet i soldered the 220nF cap like in picture.

https://imgur.com/ZFSps59

It looks dodgy but its fine. Data lanes are not short and it has continuity from pci to cap and from cap further. I tested(diode mode) all datalines and they have 0.7V

I thought that is it, i plugged it in but no picture. The computer makes post bip sound but nothing.

I then dissasembled the card and measured resistance of 5V and 1.05V and voltages:

5V 3.4k Ohm
1.05V 1.1k Ohm

Vmem 1.58V
Vcore 0.9V
1.05 missing

Measured voltages were good except 1.05V. Looked under the microscope and saw missing smd.

https://imgur.com/ieCzRIu

IC P7163 was missing 5V VDD voltage that goes through 4.7 Ohm resistor (boardview of strix version). Jumped it with 0.1mm wire and 1.05 was back on.

But still no picture.

PEX reset B11 pin is 3.3V

Flashed the bios with the one from techpowerup but same thing.

I noticed 2 more things.

First is missing smd near sli connectors.

https://imgur.com/TFISExZ

Second thing is variable voltage on capacitor near INA3221 IC.
It varies from 0V to 1.9V

https://imgur.com/8kKFUsU

If anyone has any idea for me to try, then speak out man

I dont have means to do reball.

[jiroy]

Re: Asus GTX 970 Turbo No Picture

About missing smd , it's not missing (check the attached picture) , it's only reserved for the Sli version (Same board for different versions).

About fluctuation in voltage , in my opinion , it only indicate that you need to reball .

[ktmmotocross]

Re: Asus GTX 970 Turbo No Picture

measure that u502 on what pinnu have that fluctuatin voltage

[krsta]

Re: Asus GTX 970 Turbo No Picture

measure that u502 on what pinnu have that fluctuatin voltage

It is on pin 1 and 2 that go to cap (marked in green).
IC is INA3221 (Triple-Channel, High-Side Measurement,
Shunt and Bus Voltage Monitor with I2C- and SMBUS-Compatible Interface) specs say :

Pin 1: IN–3 Analog input Connect to load side of the channel 3 shunt resistor. Bus voltage is the measurement from this pin to ground.

Pin 2: IN+3 Analog input Connect to supply side of the channel 3 shunt resistor.

The other 2 channels i see 12v steady and traces are going somewhere (probably to shunt resistor ), this channel only goes to this cap.


Also forgot to mention important thing that card is not detected in device manager when i use integrated gpu to boot to windows.

[krsta]

Re: Asus GTX 970 Turbo No Picture

Update:

Bought x1 pcie riser and gpu gives picture and drivers install.

I will revisit pcie dataline capacitor job i did, maybe put a new one.

Parts for EGA did not arrive yet.