Faulty monitor or faulty VGA cable?

stebbinsd

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Apr 22, 2017
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My desktop monitor currently doesn't display anything. It's a pitch black screen despite the computer fully functioning in the background. Also, the power button for this machine is green, not yellow, which tells me that some data is being sent to the machine. When I disconnect the VGA cable, the power button usually turns yellow.

Trying to use my monitor as a secondary display for my laptop (which I'm on right now) yields the same problem.

But here's where it gets really weird: If I press the power button to turn the monitor off for a brief moment, and then turn it back on, I will get a display on the screen for about 1.5 seconds ... only for it to suddenly go dark again.

In the brief moments I can get the monitor to work, I can see my Windows desktop image in the background, with all my icons. So that at least assures me that the computer itself is still booting up.

I also use a VGA-to-HDMI adapter. But I'm fairly certain that isn't the problem because, as mentioned before, switching to my laptop still causes the same problem of the monitor only briefly working before going black again. I can connect my VGA cable into my laptop directly, so eliminating the HDMI connector has no effect. Thus, the connector isn't the problem either.

So at this point, we've narrowed the problem down to one of two components: The monitor itself, or the VGA cable?

Is there any way to tell definitively which one is the problem?
 


"Is there any way to tell definitively which one is the problem?"
If it was a VGA cable issue:
Turning the monitor off then back on would have no effect.

Actually sounds like the rear light source (inside the monitor) is having issues.

I'm a little confused...
Does your monitor have an HDMI input?
Does your laptop or video card have an HDMI output?
If yes to both questions, test using an HDMI cable.
Alternatively, if the monitor AND video card or laptop have any other video signal types like DVI or Display Port then you should try to test with just those (no converter).
 


1. I was getting display just fine for several weeks with my adapter. So you're clearly wrong on that count.
2. I already told you in my OP that I get the same problem even if I eliminate the connector. Did you even read the OP, or did you just skim over it and look for buzzwords and just ASSUME that told you everything you needed to know?
 
1. I was getting display just fine for several weeks with my adapter. So you're clearly wrong on that count.

Would have been helpful to know in the first place.

2. I already told you in my OP that I get the same problem even if I eliminate the connector.

You weren't exactly clear on this as even Dark_Lord69 isn't sure how you have things connected.

Did you even read the OP, or did you just skim over it and look for buzzwords and just ASSUME that told you everything you needed to know?

Please keep it civil.


So let's clarify here.

What is the model number of your display?
What is the model number of your desktop graphics card/motherboard?
If this is an off the shelf computer, what model is it?
What is the model number of your laptop?

-Wolf sends
 

No idea. It's a Dell monitor, I know that much.


Geforce GTX 750 ti
Gigabyte GA-970A-UD3P


A what computer? Huh?!


Dell Latitude D630.
 
Ok.
What inputs does the Dell monitor have? Does it only have VGA or does it also have DVI, HDMI, or DisplayPort?
What outputs does the 750Ti have? Typically, it has a DisplayPort, HDMI and DVI-I, though some might have just HDMI, DVI-D and DVI-I.


The motherboard doesn't have any video outputs.
By off the shelf computer, I mean did you purchase a Dell, HP, Acer computer or one that you built yourself. Given the model number of the motherboard, I'd guess it's one you built.
Based on the specs I could find, it appears your laptop only has a VGA output

If it was working before using an HDMI to VGA adapter from your graphics card and it's not working now, it could be the HDMI port on the card.
You said it was no longer working when connecting to your laptop using just the VGA cable?

Could you please answer the bolded questions above and while I eat breakfast, maybe you could connect the display to the laptop and from the laptop try and see if changing the resolution of the secondary display has any effect.

-Wolf sends