Thanks for the advice - I have the schematic and am going to embark on the path you mention. Appreciate it. I’ll be posting videos of my progress on YT, provided I make progress. :)
On Tue, Nov 2, 2021 at 4:51 PM Bill Degnan <[email protected]> wrote: > I suppose the first thing you need is the schematics for the Zorba, anyone > have this? > > Do you have a volt meter with an ESR setting? There are caps in the > display controller board, but not too many that often are used to control > the wobble and hotiz/vert behind the potentiometers. Start with an > inspection of these caps. You should test them and replace the bad ones. > Also test caps near the voltage regulators and coming from the main power > connector. It's a bit of a shotgun approach, but if you test after each > change you might get lucky and the display will stabilize without having to > make too many repairs. You could stop at that point until something > happens again. Keep a record of which caps you replaced. It could be > something other than a cap. voltage regulators go too, but as you > describe the symptoms I would bet there is a bad cap in the display > controller board. > > If the system does not work at all it could be a power supply problem. > > Bill > > On Tue, Nov 2, 2021 at 6:22 PM Ben McAllister via cctalk < > [email protected]> wrote: > >> Hello from Seattle everyone, >> >> I'm new to the list. I recently bought a Zorba on Ebay, which was my first >> machine as a kid back in 1985, dialing into BBSs and learning assembly and >> basic. I put a lot of hours in on this machine and was very excited to >> acquire one, even though the sale was 'as is'. I have some issues to >> address, beginning with perhaps a faulty component on the video board >> driving the crt. >> >> While I'm an experienced programmer and have some rudimentary skills with >> electronics, I'm going to be in bootcamp troubleshooting this board. I >> have >> some help in my network of friends, but wanted to throw this out to the >> list. Are there any Zorba owners who would be willing to trade >> notes/advice with me on their experiences troubleshooting hardware issues >> (or anyone else out there, for that matter :) )? Have you used the >> composite video out to feed another monitor? >> >> Detail on my first issue: the display appears to need the kind of >> stabilization I _thought_ the horizontal and vertical hold adjustments >> would provide, but it's not entirely stable. I have tried the composite >> out, feeding it to a cheap composite->HDMI adapter, but that signal looks >> like a blank screen in need of vert/horiz hold adjusting. Before I go >> much >> further, I was hoping someone out there might be able to verify their use >> of the composite out to an external display. I haven't found any detail on >> what that signal should look like, other than it's 'composite' - maybe >> someone with more expertise can tell me what assumptions I can make about >> a >> composite signal. >> >> Thanks for reading that long message - and glad to be a new member of the >> list. >> Ben >> > -- -- Ben McAllister | listenfaster.com | @listenfaster | theguitarcult.com | tuktuband.com | c: 206.849.3183
