Dr. Flight's first order was for us to get a few of the Hamsters up and running again so that we'd have a development system to work with. Hence the ripping of components from an old board and putting them on a new board. Today we test out the new Hamster board.
It flatlines. This is bad.
There is much messing with oscilloscopes and multimeters to trace the captured signal through the board and find out where it stopped. Attendant crises thereof are dealt with by setting the gain on the board to something other than zero (else you get a flatline), setting the scope to read a 10X probe as a 10X probe instead of a 1X probe (else you get one tenth the amplitude—nearly a flatline), and questioning Ratso about how he removed the very expensive amplifier chip from the old board ("We stuck it in that oven thing and got it really hot so the solder melted and it just fell out of the board. Along with some other stuff."). But once we get the probe situation resolved, we find that the amplifier is working correctly. We check the next chip on down the line and see—
The A/D converter chip is stuck in backwards. So no data, hence the flatline. Luckily for us, the A/D converter is in a socket, so it's simply a matter of pulling it out and popping it back in.
Now we have three working boards, four if you count the one that's missing a power converter (we can work around that by applying the correct voltage at the contact where the power converter's output would be).
275 words | January 20, 2005 10:20 PM | Ivory tower