Moisture and VGA connections????

[Zourous]

Does anyone have any experience of knowing if moisture can cause random issues on VGA cables or devices connected to them? We have a new build and you can smell the damp around the place, although that's all I've noticed and not all of the time. There are at least 6 rooms all with Smart E70 interactive screens in them. 2 of the rooms have fixed Imacs and the other 4 have open ended VGA cables for teachers to connect their laptops into. I have one particular model of laptop (Dell E5540) that seems to be quite sensitive to the problem so I'm using this as a test although various other random reports are coming in from people with different model laptops as well who have random problems in these rooms. With the Dell laptop, it will work fine in the room with the Imac if I disconnect for a moment, but in the other 4 rooms the VGA flicks a distorted picture off and on, almost as if it's trying to connect but can't. Changing resolutions doesn't help and even running a spare loose VGA cable to the E70 doesn't help, so that almost suggests the issue is inside the E70 itself. As a side note, we do have HDMI cables attached as well and to my knowledge these have been trouble free.

 

Any help welcomed, thanks.

[davethetekkie]

How long are the cable runs in the locations where you're having the issues? Sounds like a weak analog signal and the display isn't getting sync. Do you have a powered VGA splitter or switcher you could put into the circuit for testing purposes and see if that beefs it up a bit? Maybe the Dells just aren't kicking out quite the same level of signal you're getting from your other machines?

[Zourous]

I still get problems even when I use a loose standard length 2m VGA cable and connect to the laptop. I have tried adding a video splitter but it made no difference.

[davethetekkie]

I'm presuming the displays are feeding their info back to the GPU and setting it accordingly... but what about refresh rates? Is the screen limited on what refresh rates it'll accept and behave itself? Most flatscreens are built with digital connection standards in mind rather than VGA... Maybe worth a try dropping the rate right down?

[Arthur]

Is the laptop running on battery or mains? The latter sometimes helps as the GPU switches to a lower performance mode while on battery.

 

Have you tried rebooting the laptop while connected to the projector via VGA? Does that make any difference?

[southhamster]

Can you try a similar length cable direct to the projector to try and narrow it down a bit. Could be a cheap cable which is struggling.

[southhamster]

Can you try a similar length cable direct to the projector to try and narrow it down a bit. Could be a cheap cable which is struggling.

 

Sorry scratch that I thought it was a projector .

[TommyCooper]

It'd be unusual but not unheard of to have the same fault on multiple displays. Does the flickering issue happen if a different make or model of laptop is connected? I'd want to confirm that it isn't a fault with Dell E5540 before going any further as the manufacturer will probably want to check that before authorising any warranty work.

 

If the issue is still there with a different laptop I'd get hold of all the serial numbers and contact Steljes about it (they're the warranty holder for most SMART E70s in the UK). They'll probably ask you to check a few things first but if they're under warranty I wouldn't be surprised if they suggested swapping one of them under warranty to see if it improves things for you.

[phil0569]

Have you sorted this problem yet? We have has the same issue but using HDMI to the boards. By dropping the resolution to 1360x768 cured the issues.

[Zourous]

We've moved from VGA to HDMI and it appears to be ok now for the last couple of weeks.

 

Points of note:

 

Our main model of laptop has a native resolution of 1366 x 768 and this just won't work with HDMI, so we have to drop it down one level to 1360 x 768 like you have done. I don't know if this is because of this particular resolution or just the laptop model, but it works and that's all I'm worried about.

 

I tried to link our visualizers through the HDMI and as well as the laptop and this proved a step too far. It's the same old thing, the more connection points you have the worst the signal gets. Now we go from the screen to wall plate and then wall plate to laptop and we can get away with this. The visualizer has to remain separately on the VGA. This is a pain having to educate teachers to change the screen's input, but I haven't a better option.

[Zourous]

The HDMI still proved to be problematic. After looking through the E70 manual I found that it only supports 3m for HDMI!! I was quite shocked about that as I need 7m minimum. I've now purchased HDMI repeaters and they seem to be doing the job now.