by ticso » Tue May 06, 2014 8:48 pm
Unfortunately I have to say that one of my two boards I'd received today show the same problem.
Of 10 tests about half matmul-16 went wrong.
The board with failure is SN 0003573
The good board is SN 0003957
I directly attached the heatsink and added a big fan on first powerup.
Both Zynq and Epiphany feel cool and never run hot for me.
Powersource is a workbench supply set to 5V/3A, but could do 5A as well.
I used the same setup for testing both boards - same supply cable, same supply, same SD card, same ethernet cable, ...
I didn't attach anything to USB or HDMI and just ssh to the board.
The good board take a few mA more power - currently 1.010 to 1.020 A idle.
Would have to reattach the failing board for current rate on that, but it was slightly below 1A.
The working board gets 4.69V because of cable loss - would have to measure the other one, but should be a bit higher because of lower current.
Volatage drop a few more mV during process run.
I could do retest the faulty board with raised voltage to compensate cable loss if required.
What is the upper supply limit?