Rx 580 8gb powercolor red dragon not working

[LexNox]

Hello to everyone, I've bought a not working Powercolor RX580 8GB to try to fix it; Immediately with a multimeter I've seen that on 12Vdc that we can found 8pin and 6pin connectors there is only 700Ohm between the 12Vdc power line and GND; also someone has tried to rework the board, I've seen both mosfet 4C05N are in short circuit between drain and source (bad soldering work I can say, see image).
I'll try remove the mosfets to see if the low isolation disappear, does anyone have this board? can you tell which mosfet do you have mounted? do you have some schematics? do you have a board view with the exact position of every main components?
I'll appreciate every contribute

[Bozog]

Re: Rx 580 8gb powercolor red dragon not working

Here is photos of mine if it helps

[LexNox]

Re: Rx 580 8gb powercolor red dragon not working

Thanks for the photos; may I ask you to measure resistance between 12V (6p connector) and GND? Do you get exactly an open circuit? or if not how many ohms? thanks

[Bozog]

Re: Rx 580 8gb powercolor red dragon not working

6 pin is not fitted, but starts at about 500r and rises to 1.5k, as does the 8 pin connector. I took a better photo of your reworked area.

[Bozog]

Re: Rx 580 8gb powercolor red dragon not working

Quite a few differences between the boards actually, my vcore mosfets are discrete yours are integrated power stages, bios switch in a different location, etc.

[LexNox]

Re: Rx 580 8gb powercolor red dragon not working

I've seen also this area has been touched, does anyone knows which component was the one indicated by the arrow? I think this part was dedicated to fan control.

[frankr2994]

Re: Rx 580 8gb powercolor red dragon not working

I can't answer what the missing component is. However looking at that photo it looks like someone was playing with the shunt resistors doing a power mod. I can't tell if those resistors we're replaced or it was a failed attempt to stack them regardless I think someone melted some other components off with a hot air gun. Anyways even if you find your missing part I'd make sure those 2 shunt resistors are correct.

[LexNox]

Re: Rx 580 8gb powercolor red dragon not working

Sorry, just one note I made a typo the card is Powercolor RX580 Red Devil, not Red Dragon sorry for the mistake.

[LexNox]

Re: Rx 580 8gb powercolor red dragon not working

From the pictures on this website seems that it's ok that the component is not mounted, I'll continue my investigation.

PS: My card is the golden sample one

https://videocardz.com/68228/devil-caught-in-the-act

[Bozog]

Re: Rx 580 8gb powercolor red dragon not working

I'm guessing those 2 replaced 0 ohm links route the 6pin 12v to the memory VRM and blew when it failed. I would try to ascertain if the board is repairable before wasting too much time on it, what resistance to ground do you have on the "repaired" VRM coil? It can also sometimes be useful to remove the coil to find out which side of it there may be a problem.

[LexNox]

Re: Rx 580 8gb powercolor red dragon not working

There are around 970 Ohm between R33M coil and GND