Hi there!
the card from my father-in-law suddenly went dead while on desktop. I tried a diagnosis, but found a dead end. Maybe you can help:
At first i measured all main parts. So no shorts on:
- VRMs (GPU nor RAM)
- GPU (as far as i can tell with such low resistance)
- Main power rails (12V from both peg and from pcie slot)
Then i tried measuring voltages, but there were no voltages from gpu or ram VRMs.
Next i looked at the pwm controller (uP9511P) and sure enough there is no EN signal to the chip. According to the datasheet it should be >0.4V but it stays 0V from start.
I have to admit that i also don't fully understand the EN signal line. The datasheet shows this sample circuit:
So EN is connected to GND via the resistor and the MOSFET (if voltage is supplied at the gate). But where is any Voltage coming from for the EN signal? As said it's my fault, that i don't understand the basics here.
Where is the EN signal coming from on the pcb specifically? I found the corresponding mosfet which has 5V at the gate when running. But where are the 5V coming from?
Here again the datasheet states, that the gate has to be pulled low to get the EN signal:
But what should pull the gate low?
Thanks in advance! Sorry for the missing knowledge regarding the basics. And let me know if you need more information.
the card from my father-in-law suddenly went dead while on desktop. I tried a diagnosis, but found a dead end. Maybe you can help:
At first i measured all main parts. So no shorts on:
- VRMs (GPU nor RAM)
- GPU (as far as i can tell with such low resistance)
- Main power rails (12V from both peg and from pcie slot)
Then i tried measuring voltages, but there were no voltages from gpu or ram VRMs.
Next i looked at the pwm controller (uP9511P) and sure enough there is no EN signal to the chip. According to the datasheet it should be >0.4V but it stays 0V from start.
I have to admit that i also don't fully understand the EN signal line. The datasheet shows this sample circuit:
So EN is connected to GND via the resistor and the MOSFET (if voltage is supplied at the gate). But where is any Voltage coming from for the EN signal? As said it's my fault, that i don't understand the basics here.
Where is the EN signal coming from on the pcb specifically? I found the corresponding mosfet which has 5V at the gate when running. But where are the 5V coming from?
Here again the datasheet states, that the gate has to be pulled low to get the EN signal:
But what should pull the gate low?
Thanks in advance! Sorry for the missing knowledge regarding the basics. And let me know if you need more information.