The problem ended up being a cracked solderjoint underneath the flyback transformer. I found a nice teardown tutorial that made me confident enough to crack open this Classic, and get the analog board out. Didnt take me long to spot the faulty connection. After a quick patch job, I put it back together and the video stayed steady.
The bounce didnt have any correlation to HDD activity, and when I whacked on the side of the computer, the video would jump. This is what led me to believe that a solder joint was the culprit. FWIW, this is the tear down guide I used. http://colourclassicfaq.com/highres/step2.html I plan on doing a VGA mod on one of my CC's while keeping this CC stock. It has an Apple IIe card in it, but I am missing the dongle for it. It would be nice to find one of those dongles. So, in anyone has a color classic that has a strange video bounce issue, check the flyback's connection to the board, chances are thats where the problem lies. Anyway On Nov 22, 9:48 am, hartonj <[email protected]> wrote: > It's probably something up with the input (voltage fluctuation > maybe?), or the coils (yoke?). CRTs work on the principle of electron > deflection and the coils (yoke?) around the monitor push electrons > (fired by the electron gun) towards parts of the screen on a per-pixel > level. They scan in some kind of pattern doing that if I recall. So, > if the input is higher or lower than it should be the electrons will > get pushed farther in whatever the direction of movement than they > should (even off the screen). That is, more voltage is being applied > to the coil than you want is what I think. The question is why. I'm > going to assume that this could be a capacitor problem or some kind > of issue with the input signal generation. So it would seem likely to > be either the power supply or the analog board (the bit with the > monitor controlling pieces). > . > On Nov 21, 11:25 pm, Matt Rhinesmith <[email protected]> wrote: > > > Does it synchronize with HDD activity? > > -- > > Sent from my Dell Precision 360 > > > Dell Precision 360 Workstation > > "Miranda" > > 2.8 GHz Pentium 4 HT CPU > > 1 GB RAM 40 GB and 80 GB HDDs > > Ubuntu 10.10 Maverick Meerkat -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
