G07 no picture

racer2e

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Help. My recent pole position came playing blind. No neck glow. Blown fuse. The game will be a keeper for me so I did the Bob Roberts deluxe kit, which has VR HOT and flyback. Plus I replaced the filter cap. Now I have neck glow and it snaps when I discharge it, so I've made progress, but no picture.
I've been following the Randy Fromm flowchart, and I have 150v at the big resister, so I removed x701 and rechecked. Still no pic, and still 150v. Next it says to check voltage at the can of x01. I have enough voltage there that it sparks to my meter and it's more than my meter can read. I'll bring home my fluke tomorrow and check it again, but what can cause this? Where should I check next?
Thanks, Jayme Van
 
You have 150 volts at the big resistor....what's the voltage at the other side of the big resistor?

Edward
 
It was a couple of hours ago when I checked it but I think I had 150v at both sides. I know both sides were high. Pretty sure 149 or 150v
Jayme Van
 
If the voltage is the same on both sides of the resistor, then you probably wired up the VR backwards. I did that once and had the same voltage on both sides.

Check to make sure it's wired like this:

g07r-15.jpg
 
I've had good luck recently with if the fuse is blown, just put a new fuse/hot/capkit/flyback and run with it. I've even had a few where the hot didn't blow, although the fuse was gone. I never touch the VR unless it's got serious issues going on.
 
I rechecked and I have 145 on one end ot the resister and 154v on the other end. I have 145v at the case of x01. The vr is wired as pictured.
Jayme Van
 
For giggles, even though it tested okay, replace R908. I had one that tested okay, but once I replaced it everything was fine again.
 
Good call Peale. I pulled out r908 and it was open. Installed a new one and reinstalled x701 and now it can adjust b+, but I still have no picture. I don't know for sure if this thing has a signal coming out of the video board, or if the tube is good, so I am going to swap chassis with a known good monitor.
Thanks, Jayme Van
 
Weird. I must have gotten my threads mixed up, I swear I read that you tested everything in the '900' circuit. Anyway, glad you can now adjust the B+. Turn up your screen control. If you get raster, possibly there's an issue with the game board.
 
I'd read that in other threads, so I did that. Nothing. Hopefully my other chassis will work so I'll know it's not the game board or tube.
Jayme Van
 
Good call Peale. I pulled out r908 and it was open. Installed a new one and reinstalled x701 and now it can adjust b+, but I still have no picture. I don't know for sure if this thing has a signal coming out of the video board, or if the tube is good, so I am going to swap chassis with a known good monitor.
Thanks, Jayme Van

You say you can adjust it, but not what range you can adjust it in. Can you get it to 120vdc? Does pulling X701 make it work now?

You need to start wiggling every part that is big enough to stick up from the board - and watch the solder underneath. If you think you see ANY hint of movement, reflow and add a little solder to that point....
 
If you've got a solid 120 volts on the B+ side and the heater's working, you should get a picture whether the X701 is in place or not. You're missing a broken solder joint somewhere or a crack in the board. Take a real good look at all the solder points on the neckboard socket or look for the neckboard to be cracked.

Also, did you wash this chassis under water?
 
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Yes it adjusts to 120v. No I have not pulled x701 again. It has neck glow, but with the screen control turned all the way up I get nothing. I won't get to check any more until thursday eve.
You guys have been a tremendous help. I knew nothing about monitors 8 months ago, but with your help, some careful guessing, and a bit of "shotgunning" I have fixed the monitors in 7 or 8 of my games.
Thanks again, Jayme Van
 
If everything checks out, see if you get a hint of a picture or anything just as the monitor shuts off. if so, try replacing R517. If it goes bad, it makes the colors go out one by one (depending on how bad it is). First green, then blue, then red...
 
I've seen similar issues when people install the HOT with the two wires reversed on the leads. Do you have a high voltage probe? The two times I've seen this.....I noticed the discharge "pop" was very small (unusual in a G0-7)....I stuck my high voltage probe under the anode....only 8000-9000 volts....approximately half what it should be.

Edward
 
No high voltage probe. When I swap in a chassis and neck board from another game I get video, but with serious horizontal hold, or sync issues. Similar to what that chassis does in the other cab. So it definately is the chassis or neck board that is dead. I can't find any bad solder joints and the HOT is wired the same at my other chassis.
On a side note, the other chassis is getting new pots tomorrow inhopes that that will take care of it.
Thanks, Jayme.
 
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