GTX 1660 - PLEASE POWER DOWN AND CONNECT THE PCIEe POWER CABLES(s)

[albobbyD]

Hi everyone,

I've got a GTX 1660 with a strange fault. On boot "PLEASE POWER DOWN AND CONNECT THE PCIEe POWER CABLES(s)" message appears.
Checked and re-checked the 8 pin connector on the board and on the power supply side.
I've seen that on Sense pin I've got around 3.1V without the connector. If is plugged in it goes to ground.
I've got some troubles in identifying some components. U1 has an "L2" marking and D1 a "KL7" marking.
I manage to draw a schematic with what I figure out so far.
I will need some help in identifying those components. I usually repair graphics card with Power Stage / VRM issues and I don't really understand
how the sense voltage drop is detected and by who.

Thanks in advance.

 

[RazorWind]

Can you post a photo of the board - particularly the area near the PCI-E connector?

 

[albobbyD]

Can you post a photo of the board - particularly the area near the PCI-E connector?

I don't think components are missing. I Forgot to specify that the seals were still on the card.

 

[RazorWind]

Do you have 12V at both ends of that shunt and the choke next to it?

 

[Armenius]

How is the video card being connected in the PC? I think this needs to be established before trying to diagnose a board issue.

 

[albobbyD]

Yes, I've got +12V on both ends. Checked all the fuses. The Video Card is Connected to a test bench.

 

[Armenius]

Yes, I've got +12V on both ends. Checked all the fuses. The Video Card is Connected to a test bench.

Okay, so how is power being connected to the video card in your test bench?

 

[albobbyD]

Okay, so how is power being connected to the video card in your test bench?

Honesty I use 2 power supply's. Ground is common (linked together). The motherboard is from a Dell Optiplex 3020. To power the test bench I use the original power supply. To power the video cards (External PCIe connectors) I use a server one. It could handle around 70 Amp on 12V. Ground is linked together between the power supply's. The card was bought faulty from eBay with this fault. I've tested dozens of cards with this bench and they worked just fine. The issue is with the card. I don't know how the sense pin is detected by the card. There's a via on the pcb but I can't figure where is going too because is routed internally.

 

[N4CR]

Does top left 8x pin have solder or is it just a trick of shadowing?

 

[albobbyD]

It has. Is just a shadow in the picture. I will try to have a look where that trace goes. It should definitely go to the gate of a transistor.

 

[albobbyD]

I've just sorted it out. A trace was damaged just before a via pad near Q1. Hard to spot even with 20X lenses on my microscope. Thank you very much.