Monitor problem - Loud crackle sound and flicker

[Mr. Gone]

Hey,

When I first got this MK1 a week ago, there was no problem except for maybe once when it's first turned on, or less. Should be the original, 25" monitor.

A couple days ago, it turned into a few times every start up. Today it's frightening...

Sorry the video is sidewaysish

[youtube]http://www.youtube.com/v/Gnai7ITLKCQ&hl[/youtube]

It doesn't show any signs of stopping.

Any advice would be appreciated!

[SirPeale]

http://forum.arcadecontrols.com/index.php?topic=62016.0

[grantspain]

that noise is the HT arcing to earth,either you have a crack/damaged flyback transformer,a very bad solder joint on the flyback or a damp tube which is sparking
my bet is with the first
you can prove/see the problem if you take the back door off the cab and look at the flyback to see if you get sparks

[SavannahLion]

you can prove/see the problem if you take the back door off the cab and look at the flyback to see if you get sparks

It should probably go without saying, but.... While you're at it, try not to touch anything back there while you're looking for the sparks. I fired up one of my monitors with a cracked flyback and the arc literally walked around the circuit board and frame like a spider.

[Rickn]

Yes most certainly arcing. What I saw says tube. Again take caution do not go too close to any signs of sparks especially if there is no isolation transformer. You are looking at about 25000 volts... I have been hit with as high as 45000 and the hand really gets numb.

Look at the neck of the tube a warm orange glow is nnormal ... it is the heater'

Bright flasing orange is either gassey or a dirt particle in the electron gun.

Bright blue and flashing is a sign that there is a crack in the tube somewhere, frit seal, pins or neck... in this case the tube is a gonner.

No signs of any of this power off, discharge the tube, remove the anode cap. Clean dry rag, clean all that dust off the back of the tube.

While you are at it, blow off the dust around the flyback... no compressor, use a leaf blower.

Ok after that check the solder connections on the bottom of the flyback.

Good Luck

Rick@Niemandisplays.com

[Lutus]

A DRY old ripped up T-shirt is good enough to wipe off the back of the tube.  There WILL be some grey looking stuff on the back, do not attempt to get this off as it is normal.

And NEVER use a cleaner like Windex on the back of the tube.

Couple swipes with a dry t-shirt will do it.   Just don't over do it.

[Mr. Gone]

Hey everyone. Thanks for the very helpful replies and so sorry about not reading the sticky. I'm not sure how I missed it, I try to be careful about these things.

I actually still haven't taken a look at the model #, as I seem to have eliminated the problem haven't opened it up since (which is somewhat annoying to do frequently on the thick carpet unless someone is over to nudge the cabinet with me).

Alright, so the solution might possibly make me look yet more retarded. Should the power cable have a ground prong? I don't see any direct signs of damage or previous existence of one, but if it broke off entirely I suppose it could be there. When the guy who sold it to me unloaded it from his truck, the power cable's plug got caught up under it, bending the other two prongs. It's possible that, should there have been a third one for ground, it was lost.

I'm not sure why I never really thought of this before. But I noticed that that there were absolutely no problems when using a surge protector. Anyway, if there should indeed be three prongs, I'll make sure I hold off from playing until I grab a replacement plug.

[Rickn]

Yes ideally 3 prong ground plug... but not likely related to the louud crackle and flicker. Definitely sounds like high voltage ARC.

Could be the tube, could be a cracked board around the flyback or horizontal circuit.

If you go anywhere near it powered up. we need it to be connected to an isolation transformer hopefully the cabinet has one.... or need to know if it has a switch mode power supply.

Here is what happens with an isolation transformer:
#1 the primary ground... this is like the u-ground of your ac wall outlet is isolated from the secondary ground of the transformer. This means there is not a direct return path... without it ...sort of like standing in water would be if you were playing with the Hydro.
#2 the transformer is an inductor voltage rises first and current follows later... Voltage is not the real killer it is current.

Not to scare you but think of electricity like water. You can have 100 lbs of water pressure, but if the tap is not open it goes no where.

In electricity, touch a common ground and all of a sudden all that water is hitting you at once. That is why Hydro workers have highly insulated gloves, boots, keep the tires on the ground at keep as much as they can away from water..

Ok Enough babbling from me. If you are good with all that. disconnect all power sources and start with discharging the tube I SAID DISCONNECT ALL POWER SOURCES>. now clean the back of the tube as earlier suggested.

If you are not confident with that then refer to the label that should be affixed to the monitor.. refer to qualified service technician.

Good luck

rick@niemandisplays.com

By the way, me and the guys have been around this way too long.. we laugh at each other when we get a zap... but we have the right tools in place.