K7000 (Sharp Image) - No more neck glow

Lucky1

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Hi,

I have a Sharp Image Electronics 19" monitor in my Mr. Do. Pretty much the same as a K7000 http://www.therealbobroberts.net/monitor78.html

Earlier today, the monitor worked fine, only red was really dimmed.

I was testing the RGB on the tube by grounding the neck pins on the neck board so the screen shows full Red or Green or Blue.
One end of the wire (alligator clip) was attached to the chassis and the other was touching the pin. I got green to show fullscreen...and then...I accidentally grounded the left pin (circled in red). The neck glow became very bright and then the screen faded to black. No images, no more colors, nothing.

What did I messed up by grounding that pin?

Looking at the neck board, that pin is unused. Still, it connects to the neck and I probably damaged something in the neck when it became really bright.

Thanks
 

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Last edited:
I checked the

-Voltage Regulator VR: Good

-Horizontal Output Transistors (H.O. T.) : Good

-The Fly back is not cracked and no goo is coming out.


When the power is on, there is is small buzzing sound coming from the neck board or the neck.

What is the next thing to check?
 
I accidentally grounded the left pin (circled in red). The neck glow became very bright and then the screen faded to black. No images, no more colors, nothing.

What did I messed up by grounding pin?

Looking at the neck board, that pin is unused. Still, it connects to the neck and I probably damaged something in the neck when it became really bright.

That's pin 4, unused by the chassis but internally connected to one of the other pins, probably pin 10 (heater). Remove the neckboard and check with multimeter (continuity).

https://wiki.arcadeotaku.com/images/8/8e/B10-277.jpg

If so, check if you have low resistance across pins 9 and 10 on the tube. Also check if the heater resistor on the neckboard (or main chassis) is good.
 
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That's pin 4, unused by the chassis but internally connected to one of the other pins, probably pin 10 (heater). Remove the neckboard and check with multimeter (continuity).

A: No continuity, tested all pins and pin 4 on the neck is not connected to any other pin.
 
and 9-10 have continuity (or very low resistance)?
The only continuity Is between 9 and 12.
No low resistance on any other pin combination.



On the picture, we clearly see that pin 4 is not connected to anything inside the neck.

Can I check other voltages on the neck board?
What is powering the neck to make it glow?
658f1587835c0db425a433f55574420c.jpg
 
The heater aka filament is what makes the neck glow. It's 6.3VAC across pins 9 and 10 marked "H" in the pic I posted. The point is, if you don't have continuity across those pins on the tube (with neckboard off) it means the filament is broken and you need a replacement tube.
 
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