Initially, the monitor only displayed a bright spot in the center and the rest of the vectors were extremely faded. This was with the brightness turned all the way up. So I tested the frame transistors via the wiring and everything looked ok on the DMM. Checked for shorts, everything ok. Tested all fuses, all passed continuity check. Visual inspection showed resistors are fine. Then I recapped the deflection board with a kit from arcade parts and repair. Nothing on the spec sheet indicates polarity for C703 and I'm not sure what this cap's function is. I took a guess and soldered it to the board. I've attached an image of the solder side showing the positive lead to the left. This could certainly be wrong, let me know if that is the case.
Afterward, I reconnected the board and monitor and turned on the game. The problem still remained, however. Bright spot in the center, faded vectors.... in test mode, while adjusting the X and Y pots, the screen eventually faded out and went dark. Not long after, the game stopped playing (no sound could be heard).
With the monitor unplugged, I turned the game on and noted that it could play "blind" for a good amount of time... I only waited 10 minutes or so and then shut it back off.
Today, I discharged the monitor and recapped the high voltage board. You can see after pics, showing the polarity to be correct. I think my soldering was pretty decent and when checking the leads in diode mode, I was able to get readings showing no open circuits.
After reconnecting the flyback and plugging everything in, I was greeted by a horrific scintillating sound from the yoke. The yoke was super bright.
I captured some video of this here.
At this point, I am at a loss as to what's wrong. I suspect it has a bad yoke and or tube. The tube always did take a very long time to warm up. Thoughts?