"Please power down and connect the PCI-E power cables"

[K404]

Hi all! I have a strange problem with a card, i'm hoping to get some info or ideas.

 

It has the solder holes for an 8-pin power plug, but only a 6-pin plug was installed at the factory. I get the above error message before proper POST. vCore is present.

 

I have tried shorting the other 2 pins and I have tried wiring them to the appropriate 2 pins of an 8-pin power plug. Same error message.

 

The PC has booted to Windows literally twice with this card installed, which makes me wonder if there's a bad connection somewhere but i've not been able to find it.

 

How does the card/BIOS decide that the power cable is unplugged? Do false positives exist? Can this check be pypassed?

 

Thanks!

[TerraRaptor]

You should bridge grounds of the connector

[K404]

Already tried :(... unless you mean all 5 of them?

[TerraRaptor]

https://electronics.stackexchange.com/questions/465726/what-are-sense-pins-in-8-pin-pci-express-power-plug

 

8-pin pcie has 2 sense pins. So probably you need to beidge them all

[K404]

Didn't work There's a chip beside the power plug. I'm beginning to wonder if its damaged and putting out a false warning.

[K404]

I desoldered the chip beside the PCI-E: it POSTed and booted into Windows on the first attempt!....although I get the same message if I do a warm restart. Meh. it's a bit of progress!

 

[ObscureParadox]

Huge necro bump on this, but any current sense amplifiers on the circuit at all that may have potentially failed?  

[TerraRaptor]

It is likely voltage sense rather than current sense. May also be bios issue (and then it is GPIO tied to voltage rail with divider?) - when i was binning vbioses for some cards, some bioses had this issue)

[K404]

If there was a chip failure, it was soft and I couldn't find any readings that gave it away- that's on me for not knowing enough about what values to expect.