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

Björn Ekelund bjorn at ekelund.nu
Wed Jul 14 06:22:31 EDT 2021


That's really too bad. In theory the Xilinx Zynq SOC are thermally
protected and throttles when overheating.
Could this be what is happening?

Björn SM7IUN

Den ons 14 juli 2021 kl 11:28 skrev Bob Wilson, N6TV <n6tv at arrl.net>:

> 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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