Hi Gary,
The encoders are read using an interrupt, but the keys are read as part
of the 'main loop'. I seems that the keyboard scanner has stopped
scanning because it thinks that a key is still pressed.
The schematic for the keypad board, A8 shows that there are 10K ohm
pulldown resistors on the row lines. If one of these resistors happen
to be intermittent, or have a cold solder joint, the signal would not be
'pulled down', and the scanning routine would see that row as having a
key pressed. Pressing a key causes the row line to be 'high'. The row
lines go directly to the big CPLD, which must have several I/O ports
that are used in the keyboard scanning routine. This still does not
explain why the N4PY application seems to fix the problem, or why the 15
minute wait seems to do the same.
If you look at the Logic board schematic, A7, sheet 11, you will see
that this board makes the +3.3VDC power for the Main CPU, and the two
DSP CPUs. And, there are several aluminum electrolytic capacitors used
to filter the DC. I would look at each one of those to see if the top
has bulged, or it has leaked any electrolyte. This could cause many
problems if the cap is bad. On my schematic, the caps to look at are
C402, 470 uFd/16v and C417, 100 uFd, 6.3v. While you are in there, also
check C472, 470 uFd, 16v and C470, 10 uFd, 25v. These last 2 caps are
part of the circuit to generate the +10Vdc bias for the electret
microphones. This would be similar to the problem of bad caps on the A9
power board.
The Update application has a Verify function which reads back the flash
memory and compares it to the file used in the Update Radio function.
Have you used the Verify function to confirm that the firmware download
was successful?
Again, I hope this helps find the problem.
73..
Howard, WA9AXQ
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