Attempting to power a 289w GPU with a 530w PSU is doubtful at best.

Bare minimum would be a 700w EVGA BR PSU.

Please check out my recent post here:  https://www.dell.com/community/Optiplex-Desktops/Optiplex-3010-won-t-work-with-GTX-1660-Super/m-p/8053282#M54271 

Also check out the EVGA GTX 295 specs here (includes system requirements):  https://www.evga.com/products/specs/gpu.aspx?pn=14DAB6FB-B810-4FD2-850B-EB3A1AE03211 

Good Morning, Sorry for the late reply. I have the 530w Power Supply outside the system shorted the starting pins nothing else plugged in except the GPU and the pc itself connected to the dell 265w and same thing it gives an error code of 1, 3, 4. and freezes halfway through post, I have measured the current that it draws in the working system through a high quality Multimeter and it only showed 2-10 Amps so the Power Supply is not the problem.

Try replacing the size 2032 CMOS battery.  This also resets CMOS.

Optiplex Diagnostic Lights 

And please remember using at least a 680w PSU for a 289w GPU is EVGA's recommendation.  A GPU doesn't take full power at idle, but will depending on games or etc. being played or used.

Good afternoon, I have already replaced the CR2032 battery and its same thing same code tried tinkering with bios nothing has changed.

Plus you already said PC boots with GT 1030.  It is possible the GTX 295 has a defect.  By any chance do you have another PC to try it in with a powerful enough of a PSU?

If you're out of luck, a 75w GTX 1050 ti will go great with your I7-2600.

I tried to check bottleneck potential with the GTX 295, but couldn't get it to come up.  Possibly untested with an I7-2600?  That I don't know.

Somehow the EVGA GTX 295 stalls 990 bios POST.  Have you tried clear CMOs settings of 990 by motherboard jumper reset?

@SolderingBuff,

It'll be at least a few years old by now, but do you have the latest BIOS that's for the 990?

Yep and I tried disabling SERR Messages as it said it may affect certain GPU's.

I was wondering because I have read the GTX 295 has 2 GPU's inside does that maybe have to do with it?

Yep the latest from Dell's official site its from 2018.

Yes I have tried in another system it works and boots but because it has an i5 650 it bottlenecks it so I want it to be in the Dell 990