Question B250M cannot find PCIe 16 = Bad MB??

[hobkirk]

New Win 10 install on used MB. Everything works perfectly (I think) - EXCEPT the PCIe slots.

• In slot 1 (16 and the default V card slot per the BIOS) I've tried 2 graphic cards - GTX 950 and an old POS - NO SIGNAL from both
• I put a USB 3.0 adapter into PCIe slot 2 - I stuck a USB stick in - nothing
• On-board graphics work great, BIOS updated to latest

Is there a magic trick I can try?

Gigaqbyte GA-B250M-DS3H - i5 6500

 

[Nemesia]

What is your PSU? brand and model?

 

[hobkirk]

Corsair CX430M -

• I used this same PS on yesterday's install on an MSI B250M MB that worked with the GTX card (powered by the 6 pin plug). But that MB had a broken LAN port (the entire port, including two USB 3.1 ports, glowed red constantly, and no I could not make any connection)

Thanks for your interest