You made may day with your advice to separate the part-symbols of my
sn7407 Hex Buffer. Retrospectively it seems to be obvious and certainly
all pundits had known it anyway.
However the power pins of the IC are - hidden or not - denoted as implicitly
connected to VCC and GND, respectively. This means to me no ecplicit wiring is required
as long as appropriate VCC and GND labels are specified in the
schematic. At this point I have to stand up for the TINA Design and
Analysis tool. Although TINA features sophisticated electrical analysis
and simulation of the schematic, there is no such bizarre thing like
‘connected but not driven pins’ and ‘power flags’ needed in addition to
power supplies and labels. For my Hex Buffer I had simply defined a Macro
to - implicitly - take care of all the hidden pins and later invisible
Besides the power flag concept which I account as legacy I pay all
respect to those who made this amazing KiCad tool work and available to
the open source comunity. Especially the powerfull and instant
interaction between schematic and pcb made me to stop using Tina
Back to my problem and following the given hint, in a first try I took
the IC apart and wired each module separately. Ugly but it worked.
In a next attempt all wires were removed and the modules piled up in a
staggered stack, hoping for the magic ‘implicit connections’ to the existing VCC and GND
power flags. Negative.
After making the hidden pins visible I noticed they are labled in upper/lower case letters.
Although ERC makes a remark and accepts VCC and Vcc as look-alike, Pcbnew doesn’t tolerate the spelling difference.
Finally I attached an extra label /Vcc/ to the VCC power flag and an
extra label /gnd/ to the power flag GND and - the implicit connection
The solution might not receive absolution from KiCad founders, but
after hours of wasted time for such a simple matter I will stay with it.
Concerning the buck regulator I have to postpone the issue till next
Thanks for all attempts to help solving my prob.