Nanao MS-2930-SE issues

[Esom]

I have a Nanao MS-2930-SE wirh a Toshiba tube from a New Versus City cabinet. Something is causing an intermittent overvoltage and it appears to shutdown just after energized... sometimes. Sometimes it starts right up and works happily for hours.

I have read that these monitors can crack their own necks due to similar issues, so I'm hesitant to test the chassis while on a tube too much before I've isolated the problem.

When it's acting up, there is a loud SNAP! on first power up, but I didn't see an arc or sparking. The neck glows, but no picture is produced. Once I think I heard it attempt to reenergize, but I haven't tried more than once.

So, what could be the issue? Someone just gave me a link to the schematic and I'm about to dive in, but how do I safely test the power section without actually putting it on a tube? I assume I have take the HOT out of circuit and do a bulb test, but not sure where exactly to attach the bulb leads.

 

[accskyman]

I was having a similar high voltage sound when turning mine on randomly. I usually turn it on once a month or so- it began to not work randomly then finally stopped working all together. I took the chassis out this week to ship off for repair and there was a black mark on the anode wire near the flyback. I'm wondering if it was arcing between the wire and a heatsink on the chassis when initially turning it on- maybe there was a spike that allowed it to go through the insulation on the anode wire? Worth checking on yours. I wish I would have investigated it sooner- I could have added some sort of insulation or routed it away from the heatsink more.

 

[1credit]

Clean dust of back of tube ..

Clean under anode cap

Add dielectric grease

Add silicone grease to any suspect areas around flyback ..
That could also leak high volts .

Funnily enough it’s my vs city too that does this ..

And a xc 37 Mitsubishi and the crack is super loud !