Hi,
I'm trying to fix my graphics card.
GPU resistance seems to be normal, GPU voltage is 0,9V.
Ram resistance is 97ohms but 0V.
Mosfets seems to be fine, no shorts etc.
I cannot identify what kind of two-phase controller is used for RAM.
It's in WQFN-24L package, maybe someone know what is that?
Labels:
08 2E
V1R
On pin 18 there is VCC.
Lgate: 16,19
Ugate: 14, 21
It seems to be RT8809A/B or something similar, can someone confirm that?
If that's the correct chip, then it's EN/MSEL is pulled down to GND while PC is powered on.
This EN pin is described like below:
Chip Enable and Mode Selection. This pin is a tri-state input. Pull up this pin to
exceed than 4.2V, controller operation into DEM mode. Pull up this pin to between
1.2V to 3V, controller operation into ASM mode. Pull down this pin to GND,
controller will shutdown.
This pin it going to 6th pin of sot23 6 pin chip near controller, labeled:
MA
.6
pins 2,3 are shorted and goes thru 10k resistor to 12V.
pins 1,4 GND.
pin nr 5 is going to something like a divider but without resistor to ground soldered.
What is that?