Flyback 'heat lightning'??

cueball

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I don't have the monitor model numbers, but in general what could be the cause of the current from the flyback rippling across the back of the monitor? In one case, there is also a collapsed screen (not completely but reduced dramatically). The other monitor doesn't display any picture but does the same thing.

It almost looks like one of those 'lightning balls' when they power up. I discharged and removed/replaced the anode to the back of the monitor -ensuring it was connected. Same symptoms.
 
Is it arcing around the back of the tube, where it connects to it at the suction cup, or is it arcing from the flyback itself? If it's arcing from the flyback, then it's definitely cracked. But if it's arcing at the suction cup, then you have one of a couple simple problems:

The DAG ground is not connected to the neckboard (the ground wire that goes to the spring across the back of the tube).

The picture tube is dirty. Remove the anode connection, and clean the area around it with Windex or similar - also clean the inside of the suction cup. If there is enough carbony dust in there, it can create a conductive path allowing the HV to arc to the aquadag coating.

-Ian
 
Be careful to not scrub off the aquadag coating! You just want to get the dust and dirt off, not get down to squeaky clean glass.
 
Be careful to not scrub off the aquadag coating! You just want to get the dust and dirt off, not get down to squeaky clean glass.

Good point. Yeah, I should have mentioned that. The area directly around the anode connection should be squeaky clean glass - but the rest of the tube is coated with a black graphite like paint. You only want to clean the area right around the anode connection, to ensure that a conductive path of filth hasn't built up between the anode and the aquadag coating.

-Ian
 
it is only arcing around the suction cup.. initially i thought at first the anode became disconnected under the cup, but that typically results in a clicking sound at each arc. the sound this makes is more of a woosh sound - kinda like when you press the degauss button on a crt monitor. i will also check the dag ground.

i will clean the areas as indicated, but to confirm, could this symptom cause one monitor to display a partially collapsed picture and/or no monitor at all?
 
depending on howe much hv is leaking out anything is possible.

make sure your anode cap does not have a split or "burn arc" in it..

make sure your drt ground tire is hooked up..


ive used silicone paste(silicone grease basically) around the outside edge of the cap in a pinch. not reccomended, but it has worked.
 
Silicone grease can be had at your local Auto Zone or other auto parts store. It's used inside of spark plug boots to keep them from sticking to the spark plug and tearing when you pull them off the plug.
 
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