Haven't had enough coffee yet, but wondering about that partial screen draw, failure and why you might have the same fault now with two different CRTs tested? Dunno electronics enough to be of help there, but my first blurry thought was wondering if you've got a memory failure that's screwing with the frame buffer? Dunno if you can get chimes with the the neck board unplugged in a Classic, do you get them in that config? Have you got a memory expansion card installed, if so remove it just to see what happens? The first two MB are soldered, no?Hopefully the monitor isn't shorted, and I'm 50% sure that it may not be the problem since on first power up it did actually come to life (would draw one quarter of the screen then centre the beam to a single dot very rapidly as the computer struggled to boot, the speaker clicking each time it tried to scan -- after that first attempt the computer doesn't anything except crackle the speaker and spin up the fan).
1MB is installed on the motherboard since the Classic is basically a Macintosh Plus. This is what the screen scan in question looked like. It wasn't slow enough to see it draw; it was so quick I'm sure anyone with epilepsy would go into a fit. After switching off the machine and switching it back on, nothing happens.Haven't had enough coffee yet, but wondering about that partial screen draw, failure and why you might have the same fault now with two different CRTs tested? Dunno electronics enough to be of help there, but my first blurry thought was wondering if you've got a memory failure that's screwing with the frame buffer? Dunno if you can get chimes with the the neck board unplugged in a Classic, do you get them in that config? Have you got a memory expansion card installed, if so remove it just to see what happens? The first two MB are soldered, no?
The rest of the computer is fine - it's only the when the tube is connected that the low voltage side shorts. The short is on the pins of the CRT itself.In that case I'd think I'd test the rheostat(?) that controls brightness as my first step?
Yes!Back from the repair shop! IT'S ALIIIIVE!