help with suspected blown monitor on 6 slot

hey guys
i have a 6 slot cab like the ones at the bottom of here:

http://www.hardmvs.com/xml/pacific/pacCabs.htm

a few weeks ago weird shit started to happen
i would turn it on and i would hear a really loud crackling coming from inside the cabinet.. i didnt know wtf was going on
it sounded like the 6 slot mobo was on fire lol
so i turned it off and fucked around, turned it back on and it worked.
now this has been happenin every few times i turn it on..
now today it did it pretty bad and now it turns on e.g i get the credit 0's up , i get sound but no picture.
also i got my girlfriend to turn it on, while i watched at the back door to see if i could tell where the crackling was coming from, and it was coming from the little board under the monitor. it crackled like normal for 1 second then i smelt a burning smell and the cracking stopped. im like fuck.. i bet the monitor is blown
its a nanao monitor, but it is quite old.. takes a little while to warm up etc
its done pretty bad cracking like this before, and the screen wouldnt come on for a while, and then ive tried it again a day later and its worked, but i dont think ive ever smelt burning before!

i have attached pics of wher the cracking was comin from.

thanks in advance for any help and troubleshooting you can help me with
im a total noob when it comes to monitors etc

http://img301.imageshack.us/my.php?image=hpim09876xw.jpg

http://img106.imageshack.us/my.php?image=hpim09826ak.jpg

Mine does the same thing when I turn my Astros off. The monitors works great though.

Is the sparking going on within the glass neck of the CRT ?

You might need to turn the lights out to see where the sparking is happening.

Overvoltage conditions, bad caps, cracked solder joints, components that are too close together, old hard cracked wiring insulation (especially on high voltage wires), etc... can cause popping and cracking noises.

If it's coming from cracked insulation (it's like having bad spark plug wires on your car) then you can either replace, strip back & reuse, or patch the wires with silicone compounds like RTV.

RJ

Is my situation normal?

if the neck is glowing is inside the glass then, yes, this is how crt's work. if it is coming from the board, then no, sparks on a circuit board are not normal.

edit...neck be glowing not sparking

well since the sparks last time and then the burn smell it doenst do anything at all...
machine turns on but absolutly nothing from the screen
pulled the neckboard off and no sign of burning on it.
both earths seemed fine

dunno what the go is

If it's sparking inside the tube, I'd say you have:

1. A component going out which is causing a bad overvoltage condition on the CRT.

2. An intermittant short in the CRT... Probably some chunk of crap falling off one of the elements...

3. A gassing problem - which can be caused by a crack & a slow leak into the CRT or by poorly made one.

You need to take an ohmmeter and check the driver transistors on the neck board. If the arcing was inside the CRT then you probably have some blown driver transistors.

If it's sparking outside the tube then you should look for signs of arcing on the board - little weld like looking spots on component legs where the arc jumped... or look for safety caps with little notches cut into the tops where excess voltage can purposefully jump across. If it's arcing there then you need to refer to the schematic and see where all that voltage may be coming from and look for bad components.

Also, if there's arcing on that neck board you need to go back and check those driver transistors on the neck board. If they short out you won't get video on the screen.

RJ