Aurora-R1 ALX, shuts down

Have you run system diagnostics from startup? Restart the system and at the Alienware logo start tapping F12. Run full system diagnostics. Also download and  run a CPU app that monitors Temps. Hard to believe it is a temp problem but possible. Considering what you have replace, it also could be power supply related.

https://www.howtogeek.com/howto/windows-vista/ever-wonder-what-temperature-your-cpu-is-running-at/

I have done ALL tests including the ones at startup. It usually shuts down during tests so I don't get the results. I did get results from the Assistant tests, with no problems reported.  The weird thing is that after it shuts down the light of the logo at the front remains on and blinking slowly. 
I believe it could be the power supply.
Can you tell me what is the Part Number of the Power Supply for the Aurora Alienware R1 ALX?
Thanks

The Graphics Card is a EVGA GeForce GTX 780 Ti as shown in this image:
https://www.screencast.com/t/JpeGBUcezrWW

And only one card.

Computer shuts down at random. No intense gaming because I don't do any gaming with it. It could during watching video for an hour. Or it could be after just doing different tasks. Sometimes I have it on without using it and it doesn't shut down. 

Sensors in Thermal Controller are all the time showing 23-24, so I don't see a problem of temperature. 

And yes, as you show in the picture below two cables with connectors go into the connectors black connectors shown on the picture with the arrows. And it has always been connnected this way and has always worked.
So I don't believe all of a sudden the graphic card is not accepting the connections it has always had.
That the Graphic Card could be faulty, yes it could. But before I replace a graphic card I would try with the Power Supply. Besides, the test on the graphic card was passed when it did not shut down in the middle of it. But it did pass many times.  The Power Supply cannot be tested unfortunately.  Yes, I changed everything on a hunch. First I thought it was the cooling system and then the motherboard. 

I need to know something because I never replaced a Power Supply in this machine.
I see Power Supplies that come with and without the harness for the wires. I guess if I buy one without the harness I will be able to use the harness that is already installed in the present PS. Is this correct? Or do I need to purchase the PS with all the wiring included and the harness?

So, I don't know if I should buy one like this one:
https://www.ebay.com/p/Dell-Precision-T5500-875w-Power-Supply-With-Wire-Harness-D-pn-J556t-H875ef-00/10014734668?iid=323599617138

or one like this one
https://www.ebay.com/itm/Dell-Alienware-Precision-875W-Computer-Power-Supply-J556T-N875EF-00-D875E001L/202459040797?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3D7e8a42a77143417597b367b69d5ad79b%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D142529464422%26itm%3D202459040797&_trksid=p2047675.c100005.m1851#rwid

Thanks

Part# for PSU is on the side label of what you have now, if it is 875watt then either J556T or W299G; if it is 525watts then replace with either 875w above, anyways

Desktop would shutdown after 'some use' (what 'use', light web browsing or intense gaming or just 'randomly'), then on a hunch you started replacing items to solve the shutdown, but issue remains unsolved?

What GRFX card(s) is / are in use

If two are in use, remove one & re-assess

If one is in use, & if it's the 875w model, the case harness has two GRFX cables

• each cable wears x2 connectors > a primary plus a side 'jumper'
• two cables but 4 connectors total
• (note: w/the 525w model, one GRFX cable works / one is 'dead')

If your GRFX card needs an 8pin + 6pin or dual-8pins, insert one & only one connector from off of each GRFX cable --> do not use the side jumpers when possible, see below a properly connected GFRX card --> before buying a new PSU, ensure yours is connected per photo

• if it is connected ok > may be time to replace PSU on a hunch
• if u have to deploy 2nd cable you weren't using > re-test during 'some use' & see if it still shuts off unexpectedly - if so, replace etc since they're cheap

Each GRFX cable is on its own separate 12volt rail, each rated at a weak 18amps > typically owners only use one cable while plugging both connectors in & the GRFX card trips the over-current-protection accordingly during intensive use >deploying both cables effectively gives double the power on tap & stops the PSU from shutting off

Price & condition will determine which style you buy, but if you go with one that has the case harness, message the seller for price without harness, & if forced to buy a harness > sell it afterwards $15 etc to recoup. To service yours, disconnect the black bulk connector > decouple & back chassis out > new chassis in & recouple

Consult SrvcManual &/or Alientube

The fan on a PSU can fail > to check one, inspect for movement while it's running, place hand at rear & feel for air moving or insert the end of a twist tie into the case where the fan is & within a second you know if it is spinning or not > dead fan may cause shutdown / overheating. Compressed air or air dusting w/mattress pump etc can (rarely) bring PSU back to snuff. PSU is 9 & so nearly 10years old, prolly time to replace anyways > if new PSU does not cure then it was still worthy to have good spare on hand for next time

Power supply purchased. Let's hope it does the trick. The Power Supply fan does work. I do hear it. Is it supposed to be working non stop from the moment the computer is turned on? I will need to check frequently in that case.
After the PS the only thing left is the Graphics Card. I don't believe the I/O board could be faulty to cause shut downs.
What else could be faulty? 
Let you know when I install the new PS.
Thanks for your guidance.

it turns on as a low-continuous speed always on, perhaps medium / high speed if thermally induced to cool off

I dunno why your old & new mthrbrd / CPUs randomly shut off

PSU = good suspect & likely culprit when mthrbrd proven good, time will tell

Power Supply replaced. Still shutting down. 
Afterwards did a graphic card stress test from Dell's Test. It passed.
The graphic card is an EVGA GeForce GTX780Ti. This card replaced the two graphic cards that came with the machine (much inferior quality). I feel tempted to put these two cards back to see if the GTX is faulty.
What is left? : Memory - I/O board - Graphics card- Hard Disk.
Did a Pre Boot System Assessment Tests at F12. Memory passed the test
When I do a graphic stress test with software Furmark, it shuts down practically immediately after starting. Again, can the graphics card be causing the shuts down? Could it be defective. I have never had an experience of a graphic card shutting down the computer completely. I causes screen disruptions yes but shut downs?
Could it be Windows 10 (updated until the last update)? Perhaps I should return to Windows 7?
Another interesting thing is that when it shuts down the alienware icon head at the front remains blinking slowly, usually on green color. I have to unplug the computer so that it will stop blinking. Could it be related?
Also, the other 'funny' thing is that the alienware icon head starts with a color green and after some time changes to blue. It never did this in the past before these shut down problems started. Could be it related?
I leave the computer on and it shuts down by itself after some time.
I am completely lost. After all I have replaced (cooling system-motherboard-processor-Power supply)and not solved.

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@robertolito wrote:

1. I feel tempted to put these two cards back to see if the GTX is faulty.

2. What is left? : Memory - I/O board - Graphics card- Hard Disk.

3. When I do a graphic stress test with software Furmark, it shuts down practically immediately after starting.

 

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1. I would (or at least one of them).

2. Motherboards die all the time ... especially old ones.

3. So, could be video card I suppose.

Trouble-shooting computers is more like this. Shot-gunning rarely works-out.

https://www.dell.com/community/XPS-Desktops/XPS-8700-freezes-when-playing-games/m-p/6230190/highlight/true#M20622

Yes, I still have a (perfectly working) Aurora-R1  :Cool:

https://www.dell.com/community/Alienware-General-Read-Only/Recommended-NVIDIA-graphics-cards-for-Alienware-Aurora-R1-2009/td-p/5590861

Put old GPU back. Computer has been on and no shut downs for an hour. Will confirm in a few days but looks like the culprit was the GPU.