Sorry, but I've just realized I could have misled you. It's because the best card I had for repair so far was RTX 3090Ti and I haven't had a chance to put my hands on any 40xx card yet. Looking at some RTX4080/4090 schematics I've noticed a slight change, namely for Ada Lovelace architecture proper voltage is 1.2V instead of 1.8V. I don't know how accurate your multimeter is and what range you've chosen for measurement, so 1.1V may be perfectly fine and the problem lies somewhere else.

In that case I would suggest to check power sequence, especially if 1V8/1V2 controller is setting...

Hint - if your 1V8 driver is GS9216/GS9219/AOZ2261 (I bet it's one of them), check GV-N3080EAGLE schematic and corresponding BV for instance

HI,

I don't have schematic, but your case seems relatively simple. First of all check resistance on this 1V8 rail, if it isn't overloaded. If not, check 1V8 driver voltages (should be 5V VCC and 12V VIN) - if proper voltages are present, replace the driver. If it still won't help, the culprit will be resistor divider on FB circuit. There are tons of schematis and boardviews of RTX20xx/30xx/40xx series cards here on Badcaps, I'm sure you'll find at least one with exactly the same 1V8 DC/DC converter as yours.

Regards