[hpsdr] Mercury FPGA toast... need chip!

[Chris Hinkle]

Hi,

For some reason Mercury's FPGA seems to have an internal short,
apparently just the 3V3 I/O(led D17 lights briefly when cold), as the
other 1V2 and 2V5 dummy lights are still lit and the regulators are
running at normal temps.  I have removed U15 and all else seems to be
running at normal temps and thankfully, for now, the 2208 appears to
be OK.

The main problem is acquiring a new chip, all the normal trusted
outlets (Newark, Digi-key) are showing 90+ day lead times, and I would
rather not pay for the extra 15K gates of the next available chip.  If
there is anyone out there that knows where the EP3C25Q240 can be
purchased or has an extra that I could purchase; I would be highly
appreciative.

This occurred during the testing of the LPU, the setup ran for ~28
hours, I left the room for a drink and came back to silence (no
diagnostic leds lit on either TX or RX.)  The LPU is fine, Ozy appears
to be operational (is recognized and lodes code) but the FPGA seems to
be running hot.  I have never had a reason to check the temps of any
of the large arrays until this happened so I have no reference.  Also
Penelope's FPGA appears to be suffering the same fate, as the 3V3 reg
is extremely hot and the FPGA gets extremely hot.  Checked for shorts
in the passive components and operation of the regulators involved and
those check good.  I just wanted to throw this out there in case there
was a possibility that some firmware failure or ... has caused my
predicament.


Thanks for reading,
Chris