Dual-monitor flicker on external LCD HGL30

Hey everyone,

I just purchased an acer 22'' LCD, and noticed some faint flickering when plugged into my HGL30. This flickering only happens when I have the laptop plugged into AC power, and goes away when it's on battery power. Any ideas? It's very faint, but noticeable when there is black on screen or when in a movie.

Thanks

 

If you set your power-scheme to not conserve battery power when running on batter, it will probably go away. It's a side-effect of lower power usage configurations when on battery that you just have to deal with, pretty much.

 

The grounding is also a suspect.Make sure both the laptop and the monitor have proper ground connections.

 

Pitabred,

The flickering is only observed when on AC power, and goes away during operation with battery only. Does the power profile have an effect on AC power?

Mujtaba,

I will try to play around with the grounding when I get home tonight. What do you suggest I do?

Thanks!

 

Ahhh. Sorry, I got it backwards. Reading too fast this morning Your monitor is possibly at a different ground level than your laptop. Are they (laptop and monitor) both plugged into the same outlet, or power strip? Are you using any 2-wire power in your house?

 

If you are getting a "ground loop" this will cause the flickering of your screen, and will cause a hum in your audio.

You can get a HUM X ground loop eliminator that will usually remedy these things.

 

All fixed! Plugged both the monitor and the laptop on the same power strip and the flickering is all gone.

Thanks!

 

I am not sure I am experiencing the same problem but my monitor have a shimmering/wavy problem when my HGL30 + AC is connected to my dell 24' monitor. I have the power cord connected to the same power surge and the leveling does not get rid of the shimmering/wavy. When I am on battery, the shimmering/wavy disappear. My e1505 does not exhibit this problem.

 

Ahh I spoke to soon, looks like the problem is still there. I now have both the laptop and the external LCD on the same surge protector and the flickering is still there.

FFZERO,

Looks like we're stuck in the same boat.

 

Breaking news!

After researching about this problem and looking at what different from my e1505 and hgl30. I came to the conclusion that its the extra prong plug that hgl30's adapter sport. I bought a 2-prong adapter and the shimmering/wavy problem disappear. I notice other laptop sport only two prong-outlet as well, especially a gateway laptop plug into a monitor at a local mall.

Try using something like this if you either have $5+ to spend or have an extra one lying around.

http://www.radioshack.com/product/index.jsp?productId=2104010&cp=&sr=1&origkw=2+prong&kw=2+prong&parentPage=search

 

This is VERY BAD ADVICE!

There is a reason your HGL30 has a Ground prong and it should not be bypassed by the adapter you are describing.

Go back up to post #6 and click on the link and read what it says there.

Bottom line is if you use the Ground bypass adapter...USE IT AT YOUR OWN RISK. It is not worth blowing your motherboard, video card or screen.

 

Ground prongs on anything should not be bypassed except under extreme circumstances, especially on sensitive electronics like computers. There's some more info on ground loops out there. You may consider using a different, higher-quality power strip, or not using a power strip at all, at least for testing. The problem could be between the different outlets on your power strip. See especially this page

 

I have been following this thread closely over the last few days because I am having the same problem with my Toshiba Satellite A-100 and my new Samsung 940NW LCD. Both the devices are plugged in to the same surge protector, however, I have also tried plugging them both into the same outlet and multiple outlets. I have also tried different surge protectors.

I do not have access to the circuit breakers for the house because it is in the basement apartment. I have tried disconnecting multiple TVs and cable boxes throughout the house, but to no avail. I cannot confirm that the problem is actually with the grounding (3-to-2 prong adapters are illegal in Canada)... so I am feeling a little lost. I have tried unplugging everything in the room from lights to fridges to TVs.

 

http://forum.notebookreview.com/showthread.php?t=120364

^-- I have posted a similar issue on this thread above, using the internal lcd however, on EL80.

It seems that it's off when using the laptop on battery.

In my case the entire flat is on 2 prong power, since it's a pretty old block of flats, so there is a 3-prong 'fix' admitted to the flat's power outlets (since it has been redone recently).

I'm no electrician so I guess I ought look into it and check out how exactly it is done, as I suppose having it on such a power setup not only might be causing personal interference in the matter of 'waves' on lcd, but also might not be too healthy for the hardware altogether?

Cheers,

//m.

 

Unfortunately, that's a problem with the electronics. If one uses the ground as a zero state and the other uses the neutral line, you'll run into these problems, and there's really not much you can do to fix it. It's basically that the "ground" of both the devices is different. Consider looking into a ground loop isolator. There are some tips in the different pages linked there.

 

Usually that's done by attaching a grounding cable to some exit plumbing (always has a good, cast-iron ground connection), and then to the ground line of the outlets. Assuming it was done properly I've seen lots of bad electrical work done.

 

unfortunately, I'm aware there is a lot of ****e work done, same as in this very flat- I'm afraid it wouldn't be done too proper either, recalling how the rest was done and the fact that it was done by the same crew, I'd doubt any professional work has been done in the electrical area

Well, THE ISSUE still persists tho even if on battery, I just checked. not as strong tho as on wire, but aye, still does. could the battery have been badly charged due to these wobbly lines? I heavily doubt so...

Oh well. It's not that terrible

 

I have an A100 and Samsung 905BW with this same flickering problem and this is the first reference I've found to someone else having the same issue.

I did try plugging them both into the same power strip and different outlets but none of that helped. I didn't think to grab my tester and check the grounding though.

I'll do some more experimenting tonight.

 

How about this. Since my monitor (Acer 22'') has a ground prong, can I just short the ground prong on the monitor with the ground prong on the laptop? Would that be a dangerous configuration? I have some spare wire lying around from my EE classes, but I'm not sure if they'll be enough to handle such a high voltage load.

 

Not unless you want to like like this :twitcy: or

 

That should be functionally the same as having them plugged into the same power strip. I'd guarantee you that all the grounds in a power strip share the same bus, and probably all the hot and neutral contacts, too.

 

If you figure it out, let me know

 

I haven't been able to find my tester (probably at the back of the storage closet and I can't find my Indy costume to go exploring , but I found that by plugging the laptop into one outlet, and the monitor into another outlet that the flicker either goes away or is a lot less visable. It's odd though because both outlets are still on the same circuit/fuse.

 

this seems to have made it worse for me

I will experiment a little after work.

 

Yes!!!

I just read through this thread.
Dude.
I've posted about this before, but it kinda got dismissed as people didnt quite get what was going on.

But exactly!
I have a wpa2007 20" widescreen and a HEL80.

When i have my hel80 plugged in and on the external lcd i get the waves.
when i take my hel80 off ac and run off bat, the waves go away.
I'm glad we're all on the same page now.
But yea.

fixes..

please lol
its SOOO annoying playing games. And my friends come over to see my big ass monitor..(im in highschool..we dont all have 10293801283" monitors lol...) they're like, WTF, HOW CAN YOU PLAY WITH THOSE CONSTANT WAVES!!!!
lol.

Paladin ur my hero! lol. I bought my lappy from you guys, and I cant find one thing bad about it. (other than the fingerpad reader being utterly useless..but i didnt buy it for that lol.)

 

baHA jk is a 2007WFP dell..but who cares.

 

james987 ... so are you getting the HUM X Ground Loop Eliminator?

 

I have solved my problem with Samsung LCD and Toshiba A100:

CHEAP VGA CABLE.

The cable that came with the Samsung does not appear to be a well-made cable. I stumbled upon a high quality cable from an old SGI Indy, popped it in and the waves are gone.

 

Well im thinking ofo getting the HUM X, but I'm trying to see other solutions. ^^ I have a couple of VGA cables, ill swap em around, and im also gonna try maybe getting a better surge protector.

 

Has anyone ever found a solution for this problem? I have a Dell Inspiron 1501, and recently hooked up an Envision 22" wide screen. It works fine running off the battery, but I get the wavy lines on AC power. I've updated my drivers and graphics control panel, tried different circuits, tried eliminating the ground, even sent it to the manufacturer to be repaired. Also bought a better quality cable to connect with. These lines are murder on my eyes, can anyone help???

 

Had the same problem with my HP Compaq nw8440, and using an Acer AL2216w as an external monitor for it.

Using batteries looked perfect but plug in AC power, and I could see faint banding on a darker background from bottom going up.

I researched for an hour and tested multiple outlets.
I found out that the problem is the power cable eeks out voltage interfereance through my monitor cable.
I got a heavy duty shielded vga monitor cable (About double the thickness of the flimsy one my lcd monitor came with) and it works fine now!

So just get a sheilded, thicker cable and youll be fine.
(The one I'm using that works says "Low voltage" on the side.

 

That's sound like a bad connection to me.

 

i had the same irritating flicker issue with an external monitor. Found that the problem lies with the power adapter. Call Dell to ask for an adapter that has two pins ( on the adapter itself, not the plug). It still belongs to the PA-12 family. Only downside is the 2 pin adapter is bigger in size. So, don't return your default smaller power adapter to Dell. Use the bigger 2-pin when you connect to your external monitor.

 

This may not be related but I hooked up a SOYO 24" monitor to my HP laptop and experienced a flicker/shimmer condition on the external monitor. The laptop monitor was not affected. After returning the SOYO for service they reported that it was fine.Upon further investigation and search on the internet I discovered if I up plugged my power supply the flicker/shimmer condition went away. Bottom line is the monitor cable that came with the monitor was inadequate for a 24" display. I bought a coaxial triple sheilded cable (it is twice as hefty as the original one from SOYO) designed for 19" and up monitors and no more problems.

 

Good to know...glad you asked questions.

 

The problem is caused by a ground loop. The loop is completed starting at the power connection through the power brick, into and through the laptop, through the VGA cable to the monitor, then through the monitor power cord back to the power connection. Unwanted currents circulating in this loop affect the video signals when the undesirable currents flow through the ground wires and cable shield in the video cable. This could be fixed by a well shielded (triple shielded) video cable, which prevents the loop currents from affecting the video signals.

However there is an easier and less expensive solution: plug in the power brick through a 2 to 3 pin ground adapter plug, such as Radio Shack's #61-2720. These plugs are also widely available at any hardware store. This will break the ground loop and eliminate the flickering. This fix works both with and without the HP dock.

 

A laptop computer with a grounded 3 prong plug should never be used with an adapter that removes the grounding 3rd prong.

A better solution is the HUMX Ground Loop Eliminator. You can Google for a supplier.

 

The same symptom occurred with my ASUS N80Vn and 22" V7 LCD monitor. It flickers/shimmers when connected on AC power but doesn't when it is on battery.

Tried a few suggestions listed. Plugging in the monitor and laptop into the same/different outlet. Didn't work. Finally I just swapped the VGA cable that came with my V7 monitor with the VGA cable on my Dell monitor cable. Guess what? No more flickering. It worked for me. Hopefully it will help others.