Ducksan CGM2907/ 2907M CRT monitor sparking from earth wire, no picture being di

[crisizzone]

 I'm a bit lost with this issue, I have a monitor from a Crisis Zone arcade system (also common on Silent Scope, Time Crisis 2, etc.), and when I went to turn it on I've had this experience:

• Sizzling sparks coming from the earth wires around the rear of the tube where it contacts the tube.
• Electron gun seems to be firing (can see that with the lights off), but there's no picture on the screen, the screen is just completely black.
• The H-position trimpot broke during a move (snapped in half due to weight being applied on it). This is on an isolated control board and it was the only component affected. I replaced this one today.
• Can't see any damage to the boards or any blown capacitors as far as I'm looking

I'm not sure what's happened, the neck board/neck may have been bumped during a move, but other than that I can't think of anything that would've caused this. Was working fine a year ago.

 

Mainboard is DS-2907M, neckboard is DS-2905N, control board is DS2905C

 

About the only info I can find even tangentially related is this PDF for a similar ducksan monitor: https://www.arcade-museum.com/manuals-monitors/Ducksan_CGM1301_monitor_repair.pdf

 

Anyone have any ideas?

[lilshawn]

sparking and sizzling usually indicates something majorly wrong.
when you say you can "see" the electron guns working do you mean you can see an orange glow, or is a bright blue thing going on inside?

the former means things are ok with the tube, the later means something majorly wrong. (cracked envelope)

sparking ground straps usually means HV is leaking to ground. this is very bad.

[crisizzone]

when you say you can "see" the electron guns working do you mean you can see an orange glow, or is a bright blue thing going on inside?

Lights off in the room, I can see that the electron gun is firing

[grantspain]

check the crt earth wire to the neck card is connected
lilshawn mentioned the colour of the heaters in the neck, are they orange or blue?  orange is good and blue/purple is bad

[crisizzone]

Tube neck is cracked - that's the problem here

[Ropi Jo]

Tube neck is cracked - that's the problem here

This is the most likely scenario.

You should see nothing other than the orange glow from the heaters.

[lilshawn]

Tube neck is cracked - that's the problem here

*sad trombone noises*

keep an eye out for an old CRT TV that is the same size...you could swap the tube out.

the only thing you really need to worry about is if the original/replacement tube is single focus or dual focus. i'm pretty sure your original is single focus so you'd make sure your replacement tube is single as well.

you can double check by taking the board off the neck and looking at the triangle shaped hole(s) by themselves in the connector... if it has 1 spot, it's single focus...if it has 2 it's dual focus. you can also tell if it is dual if has 2 thick wires clipped into the plastic connector. (usually white and red) while a single will have only one wire clipped into it.