Thanks for the link. I read that earlier today, but I re-read it to make sure I understood everything.

Can you recommend a new PSU? If I'm replacing the PSU, I might as well get something with more power than the stock PSU. 

Thanks

I understand that there is no way for me to verify that it is the PSU without some sophisticated tools, is there? 

I hate to start replacing components hoping I run into the right one. 

Can you try a different monitor on this PC? That would be easiest way to rule monitor out.

Is CPU overclocked in BIOS setup?

What size PSU?

Have you monitored CPU and GPU temps with something like HWMonitor (free) to see if it's overheating? Are fans racing?

Exactly what "recommended fixes" did you try, so we don't waste electrons suggesting things already tried but didn't help?

What version of BIOS? Are all your drivers up-to-date?

hello and welcome.  (and with new DP cable)

Servicing any complex machines, are a hands on task, not viable at all in text box, or phone calls.

hands and tools + skills.  (in text box? change skills to x100 and even Clairvoyance max)

Sure it can work if you want to do 100 posts, or 3 hour phone calls, (1/2 the time , less?  and be effective)

the first thing i see is you not testing the monitor on a 2 nd PC and also not telling the full symptoms and what options are in the PC (rear view of PC really helps, not shown)

"where do I go for help", well like your car , to a shop.  (my guess, no shops in town?) they have tools!

I have Video generator box i built, here a 2" square box, that i can test a monitor for days, if I had to. all by itself. see?

lacking such  tool like that use  2nd PC to test it.  what? else?

 

your U2717D, is DP connected, and you gave up in the GPU card and use the local, iGPU, onboard port. DP

the Mon has HDMI port too.hummmm

and still the screen goes black (was white fail now black)

you have replaced many things. (but not the PSU)

but tell me this , evidence:?

1: when the screen goes black do the PC fans keep spinning, heard, seen and or felt.( CPU fan and maybe PSU?)

2: does the dvd tray eject (button near tray?)  if you have one, no photo of your PC nor what is inside NOW. posted.

3: the PC beeps.>

4: the PC power light LED do odd things, mine is whitish/blue normal and amber or blink amber wrong.

5: does the monitor work on other PC's< ask friend to try or some laptops have DP ports. 

6: is the GPU card still removed, per other linked post?

7:do other monitors work this  OFFENDING PC here. (DP PORT)

8: Proving the monitor is bad first, saves lots of time,  we are not taking it apart as we do a PC. ok.

9: run overheating tests, use  free program to check CPU temps (hwinfo32.exe) 50C ok, 90C bad. that?

10: HDMI, DisplayPort output (MST)DisplayPort Mini DisplayPort (on your monitor spec page)

have SMART TV,  it has HDMI,  your PC can use  the TV as monitor, (google how) gamers love this...

my TV has no HDMI out ports, only INPUT ports, so fails. mon tests.

My HDMI monitor works plugged in to my RoKu box. (and others like this work)

Same goes for my DVD/BRD player Mon Plugged to the DVD player, HDMI,  power on, see menu.

Any thing with and HDMI OUTPUT can work (if not get out  of range error on relic monitors)

there you go,  lots of tests just for the monitor and more below.

 

11: when the monitor goes dead, does the power light on the monitor go dead, or act odd.

12: when the monitor goes dead, does the menu button work.. (see better test below)

13: when the monitor goes deed, does cycling the monitors (only) power button show that the monitor does 3 things 1: monitor splash logo then shows all ports dead, (no sig) and do it one more time.

then at the splash screen, push the button on the monitor called menu. and you must get the OSD window pop up  menu, (this works even monitor DP cable missing , yah)

on the screen? , for 15 to 60seconds (will end with warning power saver sleep mode now)

I will stop here, but you can see there are in fact lots off tests, on things complex like this.

I have more, lots more, the diagnosis logical flow chart fits a full sized wall. want one?

the goal is , which thing goes dead the PC or the monitor, so for zero progress there.

PS:

this  PC also has HDMI port too just like the MON has. try an HDMI cable.

one more test.

if the PC MON goes black

unplug the DP cable for 1 min, Makes sure MON is still on, and then plug the cable black in

the monitor MUST TELL YOU theses things, actions or text words.

port scans show all  ports dead, HDMI port and DP port dead, or OUTOF RANGE errors, NO sig errors.

or the going to sleep error,(normal if both ports are dead)

if this causes no error at all on MON screens , now, cycle monitor power only , you must get MON splash and errors or normal PC windows  desktop or the monitor is NO GOOD.

as you can see and learn there are many sets of evidence and simple test above,  and lost more and all depends on what you saw , when.(or heard)

PS2: no PCIe cards in the case right?

 

 

 

 

 

 

 

 

RoHe,

1. I tried a different monitor for a few weeks. Same problem.

2. Not over clocked in BIOS

3. Stock PSU for XPS 8930 (460w)

4. I'll try HWMonitor, but I've never heard the fans racing for more than a few seconds once in a while.

5. I tried the recommended tests in the Dell monitor forum.  The "read this before posting" by Chris M. Bought a certified 1.4 DP>DP connector. I tried using HDMI instead of DP. Changed power settings: no sleep or hibernate.

6. Bios 1.1.8 all drivers are up to date.

I don't really think it is the monitor. I get kernel-power, id 41, task 63 error. 

Thanks

self reboot, not sure that that means,  did it POST too?, or just windows, only reload.??

the former (p.o.s.t screens) smacks of power loss (or bad AC power strips?) try PC direct to wall and different wall outlet yet (also overheating any PC causes it to shut down, and I already covered that)

the latter can be , windows crashing, pure corruption on that end. (bad ram, bad hdd, bad , lots of things)

try to know this, I can not see your screens, and screens MATTER.