Memory problems on QUADRO 4000 with Dell Precision T5500 (only OS - Ubuntu)

Hi everyone

This problem description is a continuation from the Ubuntu forums (hardware):
https://ubuntuforums.org/showthread.php?t=2350791

I am able to accept that the QUADRO is likely dead, but I’m still trying to find an direct information about the core problem that caused the issue.

The main problems are shown on this pictures:
http://imgur.com/4AM5d1o
http://imgur.com/klws8Vp
http://imgur.com/RIQQVuz

Today I bought the QUADRO 600 (which is also preferred by Dell T5500 - but cheaper), so in two days I can definitely close the range on to the graphics card.

I found additional pinouts/ports on the graphics card by the side:
http://imgur.com/WlnKQs5
http://imgur.com/xpuLprK

Can I power the card externally and debug the card in specific?

Any help much appreciated, thanks in advance.

Today in the morning came the new graphics card - nVidia Quadro 600. After installation, everything works fine. No glitches on display, OS works like a charm.

On the T5500 is an other PCI x16 slot.

Are there any difficulties with connecting two graphics cards at once (display connected only to the working one - quadro 600).
I red about memory testing of graphics cards and want to try it out. That - I hope - would give me an indefinite information about bad functionality of the memory.