thanks. b On Thu, Apr 28, 2016 at 8:09 AM, Ian Primus via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Kind of covered - in my class on CRT monitor repair, I mentioned vertical problems like this, and in my old Mac class, I went over some of the basics there, but, didn't specifically get to this as it relates to Macs. It's hard to cram that much information into a one hour class - I had to move rather quickly.
The 128 uses a pair of discrete transistors for it's vertical driver. One of the caps in that circuit has failed/is failing. I'm guessing it's C6. Failing that, it's either C5 or C11. While you're in there, be sure to resolder the yoke connector, it's a very common point for cold solder joints (will cause total loss of deflection)
-Ian
On Thu, Apr 28, 2016 at 7:57 AM, william degnan via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I am thinking about working to repair the display on my '84 MAC, occasionally the horizontal is "squashed" although for now it recovers. Was this covered in any VCF E classes this or last year?
http://vintagecomputer.net/browse_thread.cfm?id=95
I assume there are a few places on the web that describe MAC repairs like these, but any comments as to what to target are welcome and will save me some time.
b
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