Apple II monitor starting to blink/flicker?

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Last seen: 1 week 2 days ago
Joined: May 22 2021 - 23:52
Posts: 5
Apple II monitor starting to blink/flicker?

Hello all - I have an Apple IIe computer connected to an Apple II monitor.  I rarely use it but when I turend it on recently I noticed that the monitor started to blink or flicker every couple minutes.  I checked and adjusted the manual monitor settings but that did nothing to change this.  Is this something I can fix without having to open up the monitor for electronics work or soldering/desoldering?  Thanks for any info on this!

Last seen: 1 hour 18 min ago
Joined: Nov 29 2020 - 19:48
Posts: 63
Identify the problem

There are several items here which could be a problem.  Any one or a combination might be at play so isolating the problem is the first step.

1) It could be the monitor failing, but I think that is the least likely.  My experience is that monitors tend to fail immediately and fully, not slowly do weird things.  Connect a TV or other monitor with composite input to check for similar behavior.  If the behavior persists, the problem is likely something else. Note not all TVs like the slightly odd video output from the Apple //, so you might get nothing, or the colors might be off.  If the problem goes away, you probably have a monitor issue.  Clean the video jack on the original monitor and try it again, perhaps with a replacement video cable. You can search AppleFritter for a recent discussion about modern Insignia TVs to use as a replacement monitor or select another replacement monitor if you don't want to venture inside the monitor. I would to this last, but I mention it first because everyone always assumes the worst.

2) The cable  could have a short.  Wiggle and lightly twist the cable to see if the problem goes away. Replace it with any RCA cable to test. This is the easiest test.

3)  The composite video port on the Apple //e is prone to dirty, broken or loose connections. This is very likely your problem.  I have attached a photo of common failure points.  Note the very oxidized video connector in the photo also.  Clean up the exterior of the connector by scuffing it with some light sandpaper or fingernail file.  You probably just need to knock the crud off, not polish it to new condition.

4) Check for broken or loose connections between the video connector at spots #1 and #2 in the photo.  People tend to wiggle the connector when connecting a cable and cause these points to fail.  A quick touch with a soldering iron and some new solder will solve the problem in 5 minutes.  I find it easier to remove the screws  from the bottom of the //e to remove the case so I have more room to work, but I have also done it with the case on.  Remove the power cord first.


Good luck.



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