Snapping/Cracking

[Chazz]

Hey guys,

Over the weekend my monitor has started making a cracking/snapping noise (something you would hear sitting in front of a fire, or when a bug hits a bug zapper).  I can also see white flickers on the screen with the cracking noise.  I don't see anything coming out of the back of the monitor.

The screen is still working fine except for the white flickers when the monitor crackels. 

Is my monitor on the way out? 

Thanks guys!

[grantspain]

its the flyback transformer,it sounds like its shorting internally but it could be arcing to the ground from a hole in the body.
its worth checking for bad solder joints around the flyback traces but  my thoughts are leaning towards a new flyback unfortunately

[SirPeale]

It could also be snapping under the anode cap from humidity. 

I'm not sure if that'll do what he's describing with the picture, though.

[grantspain]

of course it could always something as stupid as the marquee strip tube crapping out

[ChadTower]

It could also be snapping under the anode cap from humidity. 

I'm not sure if that'll do what he's describing with the picture, though.

Could be both, really... same circuit.

Turn out all of the lights and look at the anode cap while it's on.  If it's coming from the anode cap you will see tiny blue arcing from the cap to the exterior of the tube just around the cap... you will also see some "scratching" in the paint in that same spot around the cap.  That's a good sign your tube is near end of life.

[Rickn]

The white arc sort of indicates tube arcing... yes it could be flyback.

Lets hope for something easier.

Disconnect all power- yes all power. Now discharge the anode of the tube.

Just in case you do not know how... connect a jumper lead, one end to a small screw driver, other end to the ground braid on the picture tube.

Again power off!!!

Now slide the small screwdriver- make sure it is an insulated handle and do not touch the metal blade- underneath the anode.

By the way in case you do not know the anode is that thick red wire that connects to the tube .. you are sliding it under the anode cap (looks liuke a suction cup),, Snap is what you will hear.

Now take a dry cloth clean all the dust under the cap, all aroound that area of the tube as well as any space between the coating on the back of the tube that looks like it was sprayed on.

This coating is called tha aquadag ground and provides the ground return of the tube.

Now put it all back and see if it fixes the problem.

By all means if you are in doubt - call me at the shop say between 8:00 am and 2:00 pm EST and I will be happy to talk you thru it.

Good luck

Rick Nieman
Rick@niemandisplays.com
www,niemandisplays.com
519-621-1722

[ESDAVE]

hi chazz ,all good info the guys have given you but dangerous if you don't know this to begin with, try hot air from a fan heater or hair dryer with set OFF let heat go in  for about 5 minutes ,post again if need for more info. kind regards dave UK