The CRT is not bad. But to answer you, yes all CRTs from the 128K through the SE/30 are interchangeable. The Classics are a bit more problematic.
The problem is as Gregg describes. My advice to you is get Larry Pina's book, as you will most likely have to make some complicated repairs. Or you might try this document, from Dr. Tom Lee: http://68kmla.net/files/ If you are not already proficient with a soldering iron you will need to be. This could also be a simple fix in that the yoke cable has become disconnected during a look inside the case by you, or during shipping. On May 4, 8:53 am, Jeff Walther <t...@io.com> wrote: > On May 4, 3:28 am, Gregg Eshelman <g_ala...@yahoo.com> wrote: > > > --- On Mon, 5/3/10, J. Alexander Jacocks <jjaco...@gmail.com> wrote: > > > > I have a Mac 128k that _seems_ to boot fine, off of the > > > internal 400k > > > drive, based on the drive sounds, and the initial beep, at > > > power-on. > > > However, the internal CRT has a white dot at the center, > > > and nothing else. > > > Analog board problem, failure of both the horizontal and vertical drive > > circuits. High voltage > > is still working because you have the dot, there's also power to the > > deflection coils but > > they're not doing any deflecting. > > Could just be pin 1 on the logic to analog board cable. That's a > pretty common failure. Try whopping the machine on the upper left > side and see if the screen comes back for a moment. If so, find the > cable that connects the logic board to the analog board. Find the > connector at the analog board side. Remove the cardboard cover from > the outside of the analog board and desolder and then resolder pin one > of the connector. Pin 1 is the pin by itself on one side of the blank > position on the connector. > > The cardboard cover is held on with double sided sticky foam which is > available at Radio Shack (or was years ago) in a package of little > three inch strips. Scrape off the old sticky foam and replace the > cardboard cover. > > Jeff Walther > > -- > ----- > You received this message because you are a member of the Vintage Macs group. > The list FAQ is athttp://lowendmac.com/lists/vintagemacs.shtmland our > netiquette guide is athttp://www.lowendmac.com/lists/netiquette.shtml > To post to this group, send email to vintage-macs@googlegroups.com > To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com > For more options, visit this group > athttp://groups.google.com/group/vintage-macs > > Support for older Macs:http://lowendmac.com/services/ -- ----- 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 vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
