Optiplex 7010 DT PSU compatibility ?

The 1660 will not work and this forum post has more information as to why.

Thx. But if I change the PSU to 500W the 1660 will work no ?

The only version of the Dell Optiplex 7010 that supports a PSU upgrade for middle if not lower end graphic cards is the Micro Tower version last time I checked, the motherboards of the DT(Desktop) and the SFF(Small Form Factor) have issues with PSU replacements especially those meant for supplying voltage to medium or low profile gpus.

You can use supplies and cards in the smaller units.

HOWEVER they don't fit in the case.

PCI-E risers work fine and POWER supplies fit outside the case with the cover off.

https://www.ebay.com/itm/223935805785

its a standard 24in plus 4 pic connectors, i have a 500w supply hooked up and it sits outside the case,  and for my other 1st gen dell 980 it has different connector, , i got adapter on amazon for dell model to 24pin adapter , and also power supply sits outside the case, hide the pc and you will never know, and its now a gaming rig,  put any gpu that will phyiscally fit pretty much,  !SOLUTION!

Check your DisplayPort connection
You may not be aware, but usually the DisplayPort no signal issue comes from improper connection. You have to ensure that the connector has been plugged into the port correctly and it cannot be pulled out too easily. You can unplug an re-plug the DisplayPort connection

Hope this helps.