I've just finished building an Ice Tube clock kit, and digit 6 doesn't
light up most of the time. If you tap very lightly on the glass tube
with a fingernail, it will sometimes come on for a while.
I brought the boards in to the hardware lab at work, and used one of
the inspection microscopes to check the solder joints on
* the PLCC socket
* both 20-pin headers
* the VFD tube leads
I paid special attention to the connections that I _think_ are for the
VFD6 net, but since there are no pin 1 indicators on the silkscreen
for the headers and VFD tube, it's sort of hard to tell.
They all looked fine, but I re-flowed any of the ones that were even
remotely questionable and then cleaned the flux off the boards. [I've
been soldering a long time, and do a pretty good job until I get to
the really fine pitch surface mount stuff -- though I do have to use a
microscope for stuff that I didn't in my younger days.]
Can somebody point me to pin 1 positions for the headers and the VFD
tube so I can put a scope on the digit select lines to check them?
The pinout for the PLCC socket would also be great. (Or are PLC28
socket footprints all the same? It's been a lot of years since any of
my projects used PLCC sockets.)
Do VFD tubes ever have flaky digits/segments right out of the box?
I do actually have a spare tube from a previous Ice Tube kit, but I
don't have a spare board/header to solder it to -- about half the
parts in the previous kit got lost. It's a long story involving a
tornado and a couple of toddlers.
[This sure is more fun than troublshooting 7-layer boards full of BGA
parts and blind vias.]