Brent, I check that our tomorrow. Thanks Rick
On Mon, May 4, 2020 at 9:36 PM Brent Gordon <[email protected]> wrote: > This is a long-shot, but try looking at your VFD with a digital camera > (cell phone). Most digital cameras can see near infrared. If you can > see the filament glowing then you know the filament is intact. If not, > you don't know for sure. You would then have to measure the filament > current somehow. > > Brent > > On 5/4/2020 7:20 PM, Rick Bale wrote: > > Using the new logic analyzer and can see that the CPU appears to be > > working. It comes out of reset 200ms after receiving it's VCC signal. > And > > there is data on the address and data busses. Clock signals are there. > But > > it's still very difficult to understand the data I'm seeing and where to > > look. I keep thinking about the display that's off entirely. I need to > > know if the VFD is dead. I'm not sure how to test it. I did recheck the > > floating power rails and noticed some ripple on the -28V rail. It was > also > > only about -27V. I check it's filter cap and sure enough one of the caps > > was open. Easy fix. > > > > Does any one have any advice on how to verify a bad VFD without just > > replacing it? The face plate is a work of art. I don't want to > > disassemble the board as getting the LED in line again looks tedious. > The > > VFD is getting it's +40v, +5v and 0v. Should I expect to see something > on > > one spot of the VFD when it's powered up, or do I need to drive some > logic > > HI or LO into it? > > > > Thanks > > > > Rick > > > > > > > > > _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
