[Skimmertalk] 3D2AG node problems -- it's not an RP Power Supply issue, but something else

[Bob Wilson, N6TV]

Thanks for all the power supply suggestions, but at this point I'm
convinced there is nothing wrong with 3D2AG's power supply (he may have
been hearing the fan speed change in the NUC).  With Skimmer terminated, I
tried copying a large file from Windows to the RP using the SCP command,
while monitoring the Network throughput using the Windows Performance
Monitor.  The copy works for a little while, and the transfer speed peaks
at about 135 Mbps, then the SCP command seems to hang for a few seconds,
and then it aborts and reports "broken pipe", and the Ethernet connection
to the RP is reset (one of the RP's LEDs goes out, then comes back after a
little while).  I repeated this a few times, and it stopped at different
points, so it has nothing to do with disk space or with SkimSrv, just
network performance.

Bottom line:  as soon as a large amount of data is being transferred from
PC to RP or vice versa, it only works for a short time, then the connection
is dropped.  We've tried different cables, and using the Router as a
switch, and using a separate standalone Ethernet switch, and it made no
difference.  This same configuration has been working OK for months.

Antoine noticed that the RP heat sink was not solidly seated (the white
plastic tabs that hold it against the chip were apparently not pushed in
all the way).  So perhaps this chip has  been overheated too much, and now
is only marginally functional.  He reapplied thermal paste and properly
seated the heatsink, but it didn't make any difference, and xadc reports
the temperature is OK.

I think his RP is simply unfixable at this point, though there is a slight
chance this is really a Windows Update / Networking performance issue and
not an RP issue.  He has no other PC to test with.  Every time he reboots
Windows, extra "vEthernet" devices (virtual Network switches) appear in his
Network settings.  I disabled all of those and "Hyper-V" settings, but it
made no difference, the problems remain.

It looks like 3D2AG's node is kaput until a new RP or new PC can be
obtained.

73,
Bob, N6TV

On Wed, Jul 14, 2021 at 1:32 AM Björn Ekelund <bjorn at ekelund.nu> wrote:

> I have been using no-name RP 3 power supplies with good results. They are
> typically rated at 2.5A.
> Some need the 5V cable run 4-5 times through a suitable (i.e. active below
> 30MHz) clip-on ferrite to be completely quiet.
>
> Björn
>
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