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I have an Arduino Uno connected to a Buffalo 2 with an LCD via I2C. That worked great until yesterday when I decided to see what other features I wanted to add before migrating from breadboards to a real case. So, I set up an I2C isolator between the Arduino and the BII and powered everything up...no lights on the BII or the AVCC. So, I disconnected the I2C, still no lights on the BII or AVCC. What troubleshooting steps should I take? I don't see that I made any new wiring mistakes between my working state and my fried state. The Placid measures 5.5V with no load, but the output drops to 1.6V with the BII connected. Edited by user Monday, January 19, 2015 1:50:57 AM(UTC)
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Definitely sounds like a short - maybe caused by ESD (impossible for me to say)
The only thing you can do is try to remove one power supply at a time (or rather the ferrite the supplies it) and see if you can see what rail is shorted.
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Hrm. Those ferrites sure are small. Even if I managed to gracefully remove a few and the apparent short disappeared, I don't know what to do at that point, and it doesn't sound like it would be repairable at that point either.  I don't suppose you have any NOS Buffalo 2's sitting around gathering dust?
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Just how much current are you shunting ?
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My notes from when I built it say 350mA:
V(R8) 0.3582
V(R3) 0.0620
I borrowed a Fluke to build everything, but had a hard time getting any measurements with my ancient cheapo meter. Everything measured OK though.
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Just for the record - try measure voltage between tp_shunt+ and tp_out+
And do it, when the DAC is unconnected.
I might just be a power supply issue.
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Originally Posted by: avr300  measure voltage between tp_shunt+ and tp_out+ I assume tp_out+ is V+, but what is tp_shunt+? With no load, I measure .33V drop across R8, which means it's shunting 330mA, right?
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