Apple IIe display problems

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robbo007's picture
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Joined: Dec 14 2011 - 06:39
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Apple IIe display problems

Hi guys,

I'm having a pew problems with my Apple IIe PAL and an Apple II Monochrome monitor. There seems to be this watery effect going down the screen and the text is not very clear. The monitor is good as I've texted it on another Apple IIe. What things can affect the video and what can I do to try and better it or fix it?  Its hard capture on photo so I can't post any screenshots. 

 

Regards,

 

 

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Last seen: 5 hours 11 min ago
Joined: Jun 18 2010 - 13:54
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Check the video cable and rca

Check the video cable and rca jacks. Twist and wiggle the connections to see if anything changes. Also, make sure there are not any other monitors nearby (less than a foot)  that are on.

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Joined: Mar 31 2020 - 19:55
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What monitor are you using

Exactly what monitor are you using and what frequencies does it allow?  You say that you tested it on another //e. Was that also a PAL system?

 

The PAL //e is designed to work with a 50Hz 'NTSC' display. It's a particularly silly design that is neither quite NTSC, nor PAL; and if you are using a 60Hz monitor, I have no doubt that you would suffer distortion on refresh. 

 

If you want to try fine-tuning the board: Locate the following trimmers: R63, R64, C112.

 

Mark their positions with a paint pen or a fine pint felt tip, then try gently adjusting each one, a tiny turn at a time. Do this very carefully while viwing the display to see if it cleans up any distortion. 

 

The power supply can also be in question here. Too much signal noise (e.g. from bad caps or a bad transformer) could be leaking into the ground plane or otherwise causing interference. 

 

Please provide photos of the monitor that you are using, along with its ratings on the back label; of the //e mainboard so that we can identify thingfs easily for you, and of the connections and the overall output. Feel free to take a short video clip and post it on youtube. PAL //e boards are notorious for some video issues. 

robbo007's picture
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Last seen: 1 week 6 days ago
Joined: Dec 14 2011 - 06:39
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Thanks guys. In the end it

Thanks guys. In the end it seems it was the switch for colour/mono on the motherboard. I forgot all about this swtich. Someone ponted this out on another forum. Its now crystal clear. Monochrome has never looked so crisp :)

 

 

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