So I created a new problem probing GPIO pins for voltages. Tried to check pin 39 on uP9511 (VID) which is connected to GPIO0_NVVDD_PWMVID on the core.
Card then stopped outputting any voltages (5v,1.8v etc). Checked the MP1475 buck convertor that generates 5v and its shorted VIN (12v) to gnd.
Not sure why it suddenly failed (unless i shorted some pins with the probe on uP9511, but seems unlikely as they are seem unrelated in that area of the chip (pgood, vid and refadj).
Removed the chip and its shorted (had removed a couple of caps to test between VIN and GND as i thought they were causing it, but no, short was still present)
Now have to wait for some replacement chips from aliexpress to arrive at the end of the month (bought 10)
I checked with multimeter, and watched the voltage drop to 0v on the mosfet as the GPIO pin went high. I haven't checked any further to see if this changes with the card in use.
I might hook it up the the oscillopscope and monitor if it changes whilst running MATS on the 1080FE.
It its a constant 0v once initialised then pulling the pin up manually to 1.8v might help get the 1080ti card going again, not sure if the fault is with all GPIO lines or just this one. Won't be able to test that until my delivery from aliexpress arrives.
It's usb powered (using front usb connector on pc). Shows freq of 316khz. Tested the crystal on the card with this set up and it reported a pure 27mhz sine wave (no interference).
I am having a hell of a time finding this 5v short to gnd.
Chips arrived, soldered it in - tested for resistance - 1.1ohms to gnd on pin 3 (SW).
Have removed :
U27
C265
C248
C249
C251
Lifted output leg of L15 choke.
Short is to the right of the choke (as after lifting leg there is no short on u27 or c265 now), so unless it's U6 that's shorted then I am running out of ideas!
Maybe sign of GPU failing or bad GPU.
I have had identical 970 in the past. One was cool while idle, the other was 50 c while idle.
Both were repasted
While gaming the bad one initially would play just fine, after a while it would crash, the more I used it for gaming each time the earlier the crash would happen during subsequent game launch. From there it was only going down.
Comment