RichLeary
2015-05-25 05:06:40 UTC
I have decided to put the N8-4314 on the back burner for a while. Issues
that force this are:
a. As I have otherwise noted there is at least one schematic change that I
know about. That is the addition of a K1 three-pin header near RR6. However
there is no schematic for this board and the only way I noted this was a
change is by comparing the bare board to the N8-2312 layout. There may be
other changes but given the lack of a schematic those changes can only be
discovered by accident. Even in the case of the one I discovered there is
no information describing the why and wherefore of the new header.
b. There are routing changes. I discovered one while trying to track down
the cause of an issue. As was the case with the schematic there is no way
to understand them as there is no layout information.
c. The solder mask layer (red for the N8-4314) does not behave as well as
the green solder mask usually used with N8VEM boards. In particular any
solder splashes with the red mask tend to stick to the mask and removal
damages the integrity of the mask. That is not the case with my experience
with other N8VEM-associated ECB and S100 boards. In those cases any splash
does not stick to the mask and a quick poke with a toothpick will separate
the splash from the mask with no harm to the mask.
d. I have encountered at least one open trace. In the case referenced above
I was trying to determine why I was getting no SD LED response when reading
or writing to the SD card. The trace from U11-17 to U8-1 is open. I have
not found where the open is located so I will probably fix it with a wire
jumper between those two pins. That raises concern about possible other
open or fragile traces.
e. The board as currently populated has a thermal issue. I will not start
up when cold
I appeal again to the community. Someone must have schematics and layouts
fro the 4314 board. Please put them on PBWorks.
If anyone has a bare N8-2312 board they are willing to sell please let my
know.
Thanks,
Rich Leary
that force this are:
a. As I have otherwise noted there is at least one schematic change that I
know about. That is the addition of a K1 three-pin header near RR6. However
there is no schematic for this board and the only way I noted this was a
change is by comparing the bare board to the N8-2312 layout. There may be
other changes but given the lack of a schematic those changes can only be
discovered by accident. Even in the case of the one I discovered there is
no information describing the why and wherefore of the new header.
b. There are routing changes. I discovered one while trying to track down
the cause of an issue. As was the case with the schematic there is no way
to understand them as there is no layout information.
c. The solder mask layer (red for the N8-4314) does not behave as well as
the green solder mask usually used with N8VEM boards. In particular any
solder splashes with the red mask tend to stick to the mask and removal
damages the integrity of the mask. That is not the case with my experience
with other N8VEM-associated ECB and S100 boards. In those cases any splash
does not stick to the mask and a quick poke with a toothpick will separate
the splash from the mask with no harm to the mask.
d. I have encountered at least one open trace. In the case referenced above
I was trying to determine why I was getting no SD LED response when reading
or writing to the SD card. The trace from U11-17 to U8-1 is open. I have
not found where the open is located so I will probably fix it with a wire
jumper between those two pins. That raises concern about possible other
open or fragile traces.
e. The board as currently populated has a thermal issue. I will not start
up when cold
I appeal again to the community. Someone must have schematics and layouts
fro the 4314 board. Please put them on PBWorks.
If anyone has a bare N8-2312 board they are willing to sell please let my
know.
Thanks,
Rich Leary
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