G07 issue. Might be a quick fix.

Pengo13

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I have a G07 19" monitor that gets power and I can faintly see a small prism or rainbow of color that moves in the center of the screen. However, I don't get neck glow, and I can hear a faint ticking noise. Both fuses are good.

Any ideas what could be the issue? Thanks for the help.
 
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I have seen something similar when B+ was too low. Also, you can have the picture concentrated into the middle if the yoke is not connected.

The ticking noise could me a few things but my first guess is arcing due to a bad joint somewhere. Has the flyback been replaced on the G07?
 
Changed R908, X901 & X902, and went over some cold solders. Still having the same issue.

You hear high voltage kick in when the monitor is powered on, but no neck glow. B+ fluctuates between 139 and 144 (weird), and unable to adjust. Fuses are good. Slight ticking sound is heard.

Could a bad cap cause this issue, or is it more in depth?
 
I had a similar issue, but my b+ was at 162 or so. I looked at a flow chart and it led me to removing X701 and retesting. When I did this I got my full picture back. With X701 removed my b+ was maybe 142 or so. The flow chart told me that I have a bad voltage regulator.

I ordered some, will have them wednesday, and will test that theory out at that point.
 
So even though you were getting high voltage to the tube when the monitor is powered on, you had no neck glow?

I don't mind trying a new flyback, but this is a strange issue. Anyone else had to replace the flyback for this issue?

I had the same issue with no blown fuses. turned out to be the flyback.
 
So even though you were getting high voltage to the tube when the monitor is powered on, you had no neck glow?

I don't mind trying a new flyback, but this is a strange issue. Anyone else had to replace the flyback for this issue?

Neck glow exists when there is sufficient current running through the electron guns in the neck. High voltage can exist on the tube without any electron gun 'glow' present.
 
I had this exact same issue with the G07 in my Pac cocktail. It was a bad HOT. Also took out a cap or two along that circuit line.
 
So even though you were getting high voltage to the tube when the monitor is powered on, you had no neck glow?

I don't mind trying a new flyback, but this is a strange issue. Anyone else had to replace the flyback for this issue?

I had the small prism or rainbow you descibed, I dont remeber if the neck was glowing since it was awhile back, but I do remeber I had some HV cause I would get a tiny snap when discharging, not the big snap you should have right after the monitor is turned off. flyback fixed that problem for me.
 
I thought that if the flyback fails, the chassis would be completely dead. Very strange.

I will try the flyback tonight and report back.

Anyone else has experienced this issue that can chime in? Thanks

I had the small prism or rainbow you descibed, I dont remeber if the neck was glowing since it was awhile back, but I do remeber I had some HV cause I would get a tiny snap when discharging, not the big snap you should have right after the monitor is turned off. flyback fixed that problem for me.
 
I thought that if the flyback fails, the chassis would be completely dead. Very strange.

I will try the flyback tonight and report back.

Anyone else has experienced this issue that can chime in? Thanks

I was working on an FBO a couple of weeks ago. Powered up fine with a new fly, but the original would give me a B+ of +140VDC. There was a small crack in it (very small) and since the fuse had not blown, I thought that it might be fine.

Nope. Chased that around for a while before realizing it was bad.
 
Changed R908, X901 & X902, and went over some cold solders. Still having the same issue.

You hear high voltage kick in when the monitor is powered on, but no neck glow. B+ fluctuates between 139 and 144 (weird), and unable to adjust. Fuses are good. Slight ticking sound is heard.

Could a bad cap cause this issue, or is it more in depth?

You are in HV shutdown. The ticking is arcing somewhere and you need to find what is causing it. Turn off the lights and start searching for the arcing.
 
This chassis is incredibly confusing. So many different possible fixes for the same issue.......

I fixed the problem last night, and let me just say that it was not the flyback, filter cap, HOT, VR, R908, X901 or X902.

I found this thread (http://forums.arcade-museum.com/showthread.php?t=93670&highlight=g07+voltage+regulator&page=2) which pointed me to look at T501 and C511. I did not replace T501 as 'HMOON' had done, but I resoldered the transformer and replaced C511. The chassis worked perfectly after that with a beautiful picture.

The 'ticking' noise was probably the result of a bad C511 which is right next to T501. Hopefully this will help someone else with a similar issue.

Now, I can move on to the more difficult task of reviving a DOA G07 chassis which was bought as working. It has a new flyback, and cap kit already installed.....lol
 
everyone should have asked if you reacapped it, I missed ther part where you asked if a cap could do this. would have saved you some time and trouble. glad you got it working!
 
Understood. I did read, however, of others having the same problem already having done a cap kit and not fixing the issue. My guess is that the solder reflow for T501 in conjuction with replacing C511 is what did the trick.

everyone should have asked if you reacapped it, I missed ther part where you asked if a cap could do this. would have saved you some time and trouble. glad you got it working!
 
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