DisplayPort expansion card seems to have flaky connection

I’ve got the DisplayPort expansion card in the right rear bay, DIY edition, Batch 1. It worked fine for the first couple of weeks. Then one day after leaving the computer off for a few days, I turned it on and the card wasn’t being recognized (normally it shows up in the “Safely Remove Hardware” menu in the external device taskbar item). I tried rebooting and moving the card to a different bay, and nothing really helped, but then eventually the card just started working again in the original bay. Since then it’s happened a few more times on its own, sporadically. I also seem to be able to cause it fairly consistently by unplugging a DP cable from the port while the laptop is running.

I’ve tried rejiggering the EMI stickers on all four bays, but it has happened again since then.

Hi Corey, when you see this issue occur, do any error messages appear or do you hear the Windows device disconnect sound playing? Also, could you check if the device appears in Device Manager when this occurs, under “Universal Serial Bus devices”?

@nrp Been testing this some more, here are some additional details:

When I initially plug the DP card in, it makes the device connect sound and shows up in the Device Manager, sometimes after a several-second delay. Occasionally it will also show a warning message, “the functionality of this device might be limited”, but that is not consistent. Then, if I plug a DP cable into the port (connected to a Dell U2412MB monitor), the device disconnect sound plays and the device disappears.

Sometimes I get lucky and everything stays connected. Most recently it continued working for several days, and then when I disconnected the cable, the device disappeared and it started acting up again.

Thanks for the detail. Could you write into support? We may need to swap that card for you.

:white_check_mark: Done! Thanks.

Another thing I have now observed: if I leave the card in the bay, even when it is not being recognized as a device, and the DP cable plugged into the card, occasionally it will try and reconnect. Sometimes it just makes the device connect sounds and then immediately disconnects again, but I have also seen it successfully connect the device and then connect to the external monitor.