MTC9000 Anode Arcing

[Nipedley]

Hey everybody,

I was moving my machine today and noticed what looks like traces of arcing around the anode cap. Sure enough I fire it up and get a pretty blue light show. The monitor is working fine aside from this.

I've learnt from what limited experience I've had, and unfortunately that doesn't include this - so any help would be greatly appreciated. I had a go at cleaning the cap and around the hole with isopropanol but I didn't want to be too rough, what you see in the pics is after the cleaning, obviously it wasn't enough or wasn't the right tactic. There is also what looks like scoring in the anode cap.

Please let me know what I can do to sort this - new anode cap, more rigorous cleaning, grease, repainting? Some of the red paint was coming off with the isopropanol and I didn't know if that was necessarily a good thing.

Many thanks!

[lilshawn]

looks like that clip just may have been improperly installed.

you need to be sure you have both sides inside the button to have good contact.

your tube looks kinda shiny in the area not covered by the suction cup...is there a layer of grease or something on the outside of the tube? You need to eliminate the path to ground the arc is taking.

I wouldn't take soap and water to the whole thing, but anything remotely conductive on the outsides of the tube body will provide a path to ground (IE the entire area on the back of the tube painted with aquadag)

clean up anything red with a good scrub of soap and water...anything grey just gently wipe off with a cloth (be careful, aquadag will come off if wetted too much or scrubbed too vigorously.)

aquadag provides a path to ground on the back side of the tube. they usually avoid putting it around the belly button to keep it from arcing.

clean the arc traces out of the cup, carbon is just as conductive as anything else and is providing a track for the arc to get away.

[Nipedley]

Thanks for the reply I read somewhere else that dielectric grease / silicon grease is a good insulator and can be applied to the area & cup, so I've got some of that on the way.

I'll clean up the red area as you said, I think the main thing I need to do is get rid of that carbon - does anybody have any tips on how to do that? (Do I just need to be more rigorous with rubbing alcohol, or is there some other chemical I need to use, or do I perhaps need to scrape it off?)

If I can get the carbon traces off and seal it up with the dielectric grease I think I'll be alright.

[lilshawn]

a dielectric grease or sparkplug boot grease can help a bit... don't go all crazy with it though. less is more.

just wiping the cup with a cloth is usually suficent to remove carbon, you might need to scrape it off with your fingernail. carefull not to tear it.

[Nipedley]

I pulled the monitor this morning and had a go, I managed to get the arc traces off of the tube but some of the red paint around the anode hole went with it. Since the underlying material was not conductive anyway I considered this to be acceptable. Then I sealed it up with the silicon/dielectric grease and left it for half an hour before giving it a whirl.

Seems pretty successful, I kept an eye on the anode and there is no more blue lightning shooting out which is nice. There is still a slight static noise (this is with the back off and my ear close to the monitor) but its by no means threatening and with the back on and all together you can't really notice it (definately not with the speakers going)

Since there's nothing coming out of the anode cap, I'm considering that a success - do you agree or would you worry about the noise?

Thanks for your help lilshawn

[lilshawn]

i wouldn't worry too too much about it. a little static sound once in a while is pretty normal. be sure all your grounds are hooked up (not only to the metal frame but to the ground of the plug and the outlet too. It will help drain off excess static buildup and keep you from getting zapped when you touch it.

My boss had a monitor that had big buildups of static and one time when he went to clean it (while it was on) and kerzap got a pretty good static shock and bloop! the monitor went dark. turned out the ground going to the neck card was left disconnected and the static built up on it.