Computer won't switch on with displayport

CaptainRAVE · 7 Mar 2015 at 17:24

So I installed a 295x2 today along with the new Benq monitor. Seemed to work ok with a hdmi to mini DisplayPort cable. Switched to a DisplayPort to Mini DisplayPort cable and now when it is plugged in I can't turn the computer on with the power button or bring it out of sleep. Only thing that works is if I clear the cmos, take out the dp cable, then start it up and put the dp cable back in. Motherboard is a z87 d3hp. What on earth is going on?

I will try setting the default bios and check that on board graphics are disabled. Not sure what else to do!

Edit: that didn't work

stulid · 7 Mar 2015 at 17:37

Update the boards BIOS (just as a matter of course) and does a 295X2 have a switch/dual BIOS switch?

CaptainRAVE · 7 Mar 2015 at 18:04

stulid said:
Update the boards BIOS (just as a matter of course) and does a 295X2 have a switch/dual BIOS switch?

Just tried both of your ideas, still not booting with the dp in

What is interesting is that if I plug the dp cable in, my sound card lights up. If I take it out, mind sound card goes dark, so it is obviously having some kind of effect on the motherboard?

I wondered if there was a conflict with my asus xonar in the other pcie, slot. Removed that, but still the same problem.

stulid · 7 Mar 2015 at 18:23

Somethings wrong then, PSU good enough?

CaptainRAVE · 7 Mar 2015 at 18:26

stulid said:
Somethings wrong then, PSU good enough?

Coolermaster 850w. It is fine once running and benching, so I didn't immediately think of the PSU. Could be the issue though? I just don't get why the cmos keeps needing to be cleared.

stulid · 7 Mar 2015 at 18:42

Makes no sense.

CaptainRAVE · 7 Mar 2015 at 19:03

I found a microsoft basic adapter installed in the display adapters section of device manager, so have removed that. It is saying my SM Bus Controller has an issue, so am updating my intel chipset drivers. Really am trying anything I can, but I don't see how it can be any of these things.

What difference has the displayport made? Was working fine with HDMI to displayport. Why would it boot up fine disconnected, then be OK when I pluf it in later? Maybe there is a setting on the monitor that I am missing?

Mynight · 7 Mar 2015 at 19:23

Wth

.

Where'd you get the new cable from?

Have you tried the second DP on the GPU?

CaptainRAVE · 7 Mar 2015 at 19:26

So I tried my dual link dvi cable instead of DisplayPort...computer starts no problem. Argh! What is going on!!!

Downsides of a dual link Dvi cable? 60hz only I guess?

CaptainRAVE · 7 Mar 2015 at 19:27

Mynight said:
Wth .

Where'd you get the new cable from?

Have you tried the second DP on the GPU?

Have tried 3 out of the 4 so far.

I would think something faulty with the dp cable or on the card, but it works fine once booted :confused:

Mynight · 7 Mar 2015 at 19:30

I'm just trying to find the link again but searching mentioned something about dodgy cables returning a voltage that prevents the gpu turning on to protect itself.

Edit: I don't suppose you have a hdmi monitor that you could use the old cable on(just swapped around) see if it is related to either cable or gpu output.

CaptainRAVE · 7 Mar 2015 at 19:32

^^unfortunately not

Mynight said:
I'm just trying to find the link again but searching mentioned something about dodgy cables returning a voltage that prevents the gpu turning on to protect itself.

This could be what is happening. When I plug it in the sound card is lighting up, something that doesn't happen with the Dvi cable. If there isn't a way around this, I think I will return the cable tomorrow and will buy one elsewhere.

Mynight · 7 Mar 2015 at 19:46

Do you have a multimeter?

CaptainRAVE · 7 Mar 2015 at 19:52

Unfortunately not

I currently have another DisplayPort cable, so might just get a DisplayPort to mini adapter.

Mynight · 7 Mar 2015 at 19:55

Argh balls. I can only suggest trying another cable at this point then.

http://www.rage3d.com/board/showthread.php?t=33998432

Seems to indicate that a live pin on 20 can cause issues. I am unsure if this could be causing the same issues but seeing that you mentioned your audio card lighting up with DP but not HDMI it leads me to believe it may be the cause.

Apologies though it wasn't dodgy cables but more so cables that dont follow the DP specs.

Or if youre brave enough/impatient like me and the cable wasnt too much pull the 20th pin.

CaptainRAVE · 7 Mar 2015 at 19:57

Mynight said:
Argh balls. I can only suggest trying another cable at this point then.

http://www.rage3d.com/board/showthread.php?t=33998432

Seems to indicate that a live pin on 20 can cause issues. I am unsure if this could be causing the same issues but seeing that you mentioned your audio card lighting up with DP but not HDMI it leads me to believe it may be the cause.

Apologies though it wasn't dodgy cables but more so cables that dont follow the DP specs.

Well it gives me something else to try, so thank-you. Will try the cable that came with my monitor and will buy an adapter I think.

Mynight · 7 Mar 2015 at 19:59

Fingers crossed for you. I'd be very interested to know if it is indeed the cable at fault so please let me know.

CaptainRAVE · 8 Mar 2015 at 12:49

So I returned the cable this morning and picked up a dp to mini dp adapter to use on the dp cable that came with the monitor. Plugged it all in and the monitor says that no signal is detected! So I thought it might be my 295x2...nope, same problem with my 7990. So it could be a monitor issue, but I have no other monitor that I can try. I might see if I can buy a mini dp to dp cable from somewhere else or will order one on ocuk if that fails. I can't belive that I am in a worse position today!

CaptainRAVE · 8 Mar 2015 at 13:29

SOLVED.

Plugged in Dvi, booted with that. Switched to dp and now the pc seems to boot ok with just dp plugged in.

Solution, don't buy the dp to mini dp cable from maplin since it returns a voltage that causes the computer not to boot.

Mynight · 8 Mar 2015 at 14:22

Yay! Glad it's sorted

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