Hello guys,
A friend gave me a GPU Radeon Sapphire Pulse RX580 8gb pretended to be dead. No power at all. I thought it could be a good idea with a bit of research to fix this board regarding to the amount of videos related to GPU repairs saying it's mostly dead mosfet in this case when 12V fuses blow up.. I have a Lab PSU, my multimeter, hot air gun and can solder correctly, also a microscope.. After few readings, i don't know where im going because the problem is nothing like the repairs videos show. In my case, the 2 12V fuses, close to the 8 pins connectors, have blown but i don't find short to ground after this broken fuses...
No short on the 3.3v, aux or 5v rail etheir...
So i tried to inject small voltage on the 12V rail after the 8pin connector but no amp is taken at all....
I found a short between VSS and VDD pins of a NCP81022 chip on the right end side of the board close to the mosfets line.. but not between ground and Vin of the chip.
I tried to find shorts obviously some caps are, some of them on the GPU ic itself but i heard its because of low resistance caps in some area..
I checked the 4 mosfet on the right side, they are no shorted.
I join a picture to my reply with colored dots to give more infos about the board : first of all, I have approx 30 OHM impedance on the yellow dots linked to coils. Fall to 1 ohm on the coils (red dots) close to the mosfets. Then 0,1 ohm on the left of the CMS caps (light blue dots). 22 OHM on the blue dots coil bottom left.
The main thing is i thought i could try to inject low voltage with my psu, right after the blown fuses but he doesn't take any amps, i don't know why.
I would like to know if there is a way to check if the GPU IC itself is dead and it's game over (because i won't be planning a BGA reballing). I heard if you feed voltage on the 12v rail and you have the exact same voltage that goes to the GPU ic, it means it's game over.. but i don't know where to check. If i inject 1V, the Upper mosfet take half of it but the three others take 1V at their Vin.. but once again no amps taken..
Thank you for your help. May be im wasting my time with this board but as we say, live and learn. Electronic is fascinating but it's lifelong road.
Cheers
Geeom
A friend gave me a GPU Radeon Sapphire Pulse RX580 8gb pretended to be dead. No power at all. I thought it could be a good idea with a bit of research to fix this board regarding to the amount of videos related to GPU repairs saying it's mostly dead mosfet in this case when 12V fuses blow up.. I have a Lab PSU, my multimeter, hot air gun and can solder correctly, also a microscope.. After few readings, i don't know where im going because the problem is nothing like the repairs videos show. In my case, the 2 12V fuses, close to the 8 pins connectors, have blown but i don't find short to ground after this broken fuses...
No short on the 3.3v, aux or 5v rail etheir...
So i tried to inject small voltage on the 12V rail after the 8pin connector but no amp is taken at all....
I found a short between VSS and VDD pins of a NCP81022 chip on the right end side of the board close to the mosfets line.. but not between ground and Vin of the chip.
I tried to find shorts obviously some caps are, some of them on the GPU ic itself but i heard its because of low resistance caps in some area..
I checked the 4 mosfet on the right side, they are no shorted.
I join a picture to my reply with colored dots to give more infos about the board : first of all, I have approx 30 OHM impedance on the yellow dots linked to coils. Fall to 1 ohm on the coils (red dots) close to the mosfets. Then 0,1 ohm on the left of the CMS caps (light blue dots). 22 OHM on the blue dots coil bottom left.
The main thing is i thought i could try to inject low voltage with my psu, right after the blown fuses but he doesn't take any amps, i don't know why.
I would like to know if there is a way to check if the GPU IC itself is dead and it's game over (because i won't be planning a BGA reballing). I heard if you feed voltage on the 12v rail and you have the exact same voltage that goes to the GPU ic, it means it's game over.. but i don't know where to check. If i inject 1V, the Upper mosfet take half of it but the three others take 1V at their Vin.. but once again no amps taken..
Thank you for your help. May be im wasting my time with this board but as we say, live and learn. Electronic is fascinating but it's lifelong road.
Cheers
Geeom