Monitor Gurus...Screen 'Pulses' Sometimes...Stops when you JOLT the Monitor !

[Charles4400]

So my NEC XM29 works fine most of the time but sometimes when I turn it on the Screen Seems to 'shake' or 'pulse' intermittenly. When this happens the pulsing is slight but consistent and definately enough to be noticable and extremely annoying.

The way I have been fixing this is through brute force method of jolting the monitor by lifting it a few inches on one side and letting it drop shaking the whole thing!

It works when I do this (which is interesting enough!) and the screen stays stable....But every few days the pulsing will start again and I must repeat the process. Only problem is when I put this baby into my soon to be cabinet there is going to be no way to remedy this with my brute force method.

What is really wrong with the monitor and how can I make sure the pulsing doesnt come back?
Do I need to tighten something internally to keep the shake out?

I have triple checked the connections making sure the vga cable is tight and in place on both the monitor and graphics card on the computer.

Anyone experienced this pulsating screen syndrome and how did you fix it?

[grantspain]

hahaha,nice one
you have a bad solder joint or a bad connector somewhere,you need to attend to this as what you are doing atm is not good for the monitor

[Mauzy]

Jesus! How long have you been dropping your monitor?

[Charles4400]

hahaha,nice one
you have a bad solder joint or a bad connector somewhere,you need to attend to this as what you are doing atm is not good for <the monitor</a></a>

So if i am using the VGA input on the monitor would the bad solder or connection be from that....or could it be somewhere independent of the vga connection and the problem lies with the actual monitor connections itself?

Jesus! How long have you been dropping your monitor?

Heh I know it sounds bad (well I guess it actually is bad !  ) but it's the only way I figured out how to solve the problem! And by dropping it...well more like jolting it...it is currently on carpet at least  !

[Kevin Mullins]

So if i am using the VGA input on the monitor would the bad solder or connection be from that....or could it be somewhere independent of the vga connection and the problem lies with the actual monitor connections itself?

You need to physical open the monitor up..... and check for bad solder joints.
Most likely on the YOKE connector going from the tube to the main chassis. (four large pins)

[Mauzy]

Wait: is this an arcade monitor or a computer type monitor with a plastic case and such?

[Charles4400]

So if i am using the VGA input on the monitor would the bad solder or connection be from that....or could it be somewhere independent of the vga connection and the problem lies with the actual monitor connections itself?

You need to physical open the monitor up..... and check for bad solder joints.
Most likely on the YOKE connector going from the tube to the main chassis. (four large pins)

Thanks I don;t know what a yoke is but will look for four large pins as you mentioned. (Don't know how much proding I will do near the tube though as I'm afraid of getting electricuted from what I've read about monitors! 

Wait: is this an arcade monitor or a computer type monitor with a plastic case and such?

It is technically a computer monitor and does have a casing around it (though the cool thing about this monitor is that it was condisered a 'presentation' monitor which allows it to desplay very low resolutions....so it acts as an arcade monitor and higher resolution monitor as well!)

[Kevin Mullins]

The yoke is the copper coil attached to the neck of the glass tube itself.
Look for four larger wires like BLUE, YELLOW, RED GREEN. (could be different colors, same location though)
Follow those to the main chassis, should be a fairly large easy to identify connector.
Check /resolder the solder joints on the bottom side of the chassis where that plugs in.

DON'T mess with the big thick RED wire with the suction cup stuck to the tube.
Read up on discharging if you feel confident in doing so.

[Mauzy]

Wait: is this an arcade monitor or a computer type monitor with a plastic case and such?

It is technically a computer monitor and does have a casing around it (though the cool thing about this monitor is that it was condisered a 'presentation' monitor which allows it to desplay very low resolutions....so it acts as an arcade monitor and higher resolution monitor as well!)

Oh cool. I don't know why but I don't find it NEAR as shocking (ha!) that you're knocking around a computer type monitor. I can't give you too much flack for that anyhow. My computer monitor takes a good beating now and then. 

[Jack Burton]

My XC37 does a similar thing. The picture shakes on startup, and after a while it starts flickering badly and going back and forth between light and clear, and dark and blurry.

I haven't lifted it and dropped cause, well, I can't, the thing weighs more than my house.

Is this similar to yours Charles?

 

[Charles4400]

Thanks for that Pic Kevin...that certainly helps and I'll let you know what I find when I start undoing the case areound the tube (just got my mame cab in and have been assembling that so havent messed with the monitor yet)

I don't know what an XC37 is Jack but the XM29 does weigh a TON ! I think it weighs 120 lbs or something like that. It has built in handles on the top and I just lift 1 side and drop it a few inches on the carpet (its not in the cab yet as the cab isn't finished). Though I can't say this is the cure all method for the screen anomolies...and can't say I recommend the drp method...it just happens to work on mine   !

[Jack Burton]

The XC3717c is a presention monitor like yours, except the screen is 37" instead of 29".  and it weighs 270lbs!

[Charles4400]

... the screen is 37" instead of 29".  and it weighs 270lbs!

  AWESOME!

You HAVE to get that baby fixed! That's too nice of a monitor!

[Ummon]

All this would seem a lot less mysterious and wonderful (though more interesting in other ways - as well as SAFER), if you two (mauzy and charles) read the monitor section of the wiki.

[Jack Burton]

Read the whole thing a while back.

At first, my reading told me that the flyback had a crack in it, since the monitor made a buzzing noise and clicked and zapped every once in a while.  It has since stopped, so I'm not sure what that was all about, but I have inspected the flyback and it looks ok from the outside, plus the buzzing was coming off the neckboard.  Maybe I set it back correctly when I took the neckboard off. 

But the intermittent darkness and blurriness persists.

I have of course taken the back off and adjusted the focus and screen settings, it helped tremendously, but still didn't solve the problem.

I have read and heard a few causes for what my monitor is doing.  A tech at a television repair shop says that it could be build up of carbon inside tube and recommend rejuventation.  But I don't think he is right.  Plus, I don't know anybody with a rejuventator that will work for this monitor.

Grantspain recommended to me that perhaps a pin on the neckboard connector was bent.  So I took that off and made sure all the pins were in their right place, which they were. 

After looking at this thread I looked at all the solder points on the neckboard, and they look good to me.  It may be a case of bad solder though, and I will have to get a multi-meter and check each point. 

Oh, and I would NEVER drop my monitor.  That was a joke.  Charles4400, I'm sorry, but all dropping it is going to do is  cause more malfunctions.

[Kevin Mullins]

After looking at this thread I looked at all the solder points on the neckboard, and they look good to me.  It may be a case of bad solder though, and I will have to get a multi-meter and check each point. 

And you plan to look at the solder joints on the main chassis right ?
(which is what I was referring to)

[Jack Burton]

I looked around the whole of the monitor to see if I could find anything that looked anomolous, but I'm not sure if I would even be able to tell if something was bad or not.  I don't see anything that looks like it isn't fully connected, or solder that is dark or looks like it peeling off of anything. 

Do you have a link to something that looks like what you are talking about?

[Kevin Mullins]

Found a couple on the web ......

[Jack Burton]

Thanks for the pics.  They will help out a lot. 

Is this a problem you have seen before Kevin?