I replied to an earlier post on this but I don't think anyone saw it so I'm reposting as a new Thread:
What a coincidence, I went to look at a game I was having monitor troubles with and it is this exact one. I looked at the following from Ken's page:Common problems: Power applied, Monitor dead, No neck glow. Cause: Resistor R812, Transistor Q801, and Capacitor C807 are all bad and should be all replaced. Solution: Replace R812 (68 ohms, 1/2 watt), Q801 (2SC2073 or 2SD478 or NTE 375), and C807 (100 uf @ 16 volts). Check zener diode (7.5 volt) D805 for a shorted condition.
Top half of picture distorted (may have edge ripples in bad half, too). Cause: bad I302 chip. Solution: Replace I302 vertical output IC (LA7833). This IC should have high resistance (500k or higher) between pin 1 and the mounting tab. If resistance is considerably lower then the IC is bad internally.
It appears someone already worked on this chassis and replaced all the Resistors,Transistors,and caps mentioned above. I did notice that the Q801 looked burnt and the solder joints were loose so I removed the old solder and reflowed everything above.
Well I thought that did it cause the monitor fired right up with a nice picture, then I started hearing a sound (best way to describe is the static sound you get when playing an old scratched up record) and then the picture went out. A few seconds later it would come on again, make that noise and go out again. I can't tell where the sound is coming from it almost sounds like it's coming from that Yellow transformer looking thing in the picture earlier in this thread. It doesn't sound like it's the flyback and the flyback adjustments work fine. I did notice that when I hear that sound the screen starts to ripple on both Sides(top to bottom-not just one half like mentioned by Ken). Anyone know what my problem could most likely be?
Thanks
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What a coincidence, I went to look at a game I was having monitor troubles with and it is this exact one. I looked at the following from Ken's page:Common problems: Power applied, Monitor dead, No neck glow. Cause: Resistor R812, Transistor Q801, and Capacitor C807 are all bad and should be all replaced. Solution: Replace R812 (68 ohms, 1/2 watt), Q801 (2SC2073 or 2SD478 or NTE 375), and C807 (100 uf @ 16 volts). Check zener diode (7.5 volt) D805 for a shorted condition.
Top half of picture distorted (may have edge ripples in bad half, too). Cause: bad I302 chip. Solution: Replace I302 vertical output IC (LA7833). This IC should have high resistance (500k or higher) between pin 1 and the mounting tab. If resistance is considerably lower then the IC is bad internally.
It appears someone already worked on this chassis and replaced all the Resistors,Transistors,and caps mentioned above. I did notice that the Q801 looked burnt and the solder joints were loose so I removed the old solder and reflowed everything above.
Well I thought that did it cause the monitor fired right up with a nice picture, then I started hearing a sound (best way to describe is the static sound you get when playing an old scratched up record) and then the picture went out. A few seconds later it would come on again, make that noise and go out again. I can't tell where the sound is coming from it almost sounds like it's coming from that Yellow transformer looking thing in the picture earlier in this thread. It doesn't sound like it's the flyback and the flyback adjustments work fine. I did notice that when I hear that sound the screen starts to ripple on both Sides(top to bottom-not just one half like mentioned by Ken). Anyone know what my problem could most likely be?
Thanks
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