Dears repair gurus,
first of all, sorry for the english, I am using this forum through google translate. Thank you for the stuff which you are doing here.

My friend sent me card which he got - its huge old Ati HD 5970. This dualchip monster has an issue - black screen and fans are running 100%. Windows are not able to detect it. What I found out


vcore voltage is OK, ram voltage is OK, some support voltages are ok (1,5V), 3,3V is also ok and on bios. The only missing voltage is marked by green and I have no idea for what should be this pwm set. On 1st mosfet there is 12V, gates are not shorted, driver from other site seems to be OK, but simply it not gives any voltage. Cores are heating up.

I tried to reflash bioses (each chip has separated) but pm25lv010 I am not able to erase with my CH341A even if pin3 is not grounded and connected to pin8 (vcc)

If the core or vrams would be dead, it can be seen by system atleast, but this looks like completly not connected.

Kindly asking for any advice what to check, thank you!!

For two-chip cards you shoud start with ensuring that the central PCIe bridge is working:

Find its power line (analyze where capacitors on the other side of card under the bridge are connected), verify that it isn;t in short circuit (at least 5Ohm I think) and has voltage.

If it is powered - it should be visible in device manager as PCIe bridge, even without GPUs. (boot with monitor plugged in motherboard video).

Fot two-gppu card if both of them are not visible in device manager -the bridge is the problem. The gpus are not tighly related and even if one of them is dead - the other would be working fine

Take a motherboard with a PCI slot on board.
Boot into DOS with a PCI video card.
Run "atiflash" with the switch "-i" / "- ai".
With a valid PCI bridge, the program will show you the GPU.

Hello guys,
thank you for help, you were right pcie bridge is dead. The missing voltage which I marked on the picture is for bridge chip. Phase is shorted (0,2 ohm) and after connecting 1V it drains more than 5amp.

Thank you again!