I had received a Televideo Personal Terminal which was dead. With an ohmmeter, it measured no continuity across the AC line but the fuse was good. I thought I had an open power transformer but then I was looking at other Televideo schematics and see it has a switch for 110/220 which puts the two primary windings in series for 220v or parallel for 110v. I verified it was set for 110v. I then realized both windings would have to be open which was highly unlikely. I traced the
primary circuit and found the open was in the 110/220 switch. What had happened was the screws mounting the switch were loose which allowed the switch to slide. When I tightened the screws, power was restored !! I'm a noob when it comes to using this forum but I think I've attached a picture of my Compupro system running Wordstar on this terminal. It has a very slight 60hz crawl travelling down the screen. In normal NTSC television displays, if there is a crawl it normally moves up the screen because the vertical scan rate is 59.94hz. This vertical rate must be higher than 60? Sorry, it's late and my brain likes to wander. A picture "might" be attached. Fun stuff !!
Larry G
primary circuit and found the open was in the 110/220 switch. What had happened was the screws mounting the switch were loose which allowed the switch to slide. When I tightened the screws, power was restored !! I'm a noob when it comes to using this forum but I think I've attached a picture of my Compupro system running Wordstar on this terminal. It has a very slight 60hz crawl travelling down the screen. In normal NTSC television displays, if there is a crawl it normally moves up the screen because the vertical scan rate is 59.94hz. This vertical rate must be higher than 60? Sorry, it's late and my brain likes to wander. A picture "might" be attached. Fun stuff !!
Larry G