Subject: Burn in test on the A2052 Results From: Alex Asen Date: Mon, 30 Jul 2007 11:28:36 -0400 To: Kevan Hashemi Test began at 10AM on July 9 with three randomly selected A2052 boards that had been modified with new a 100-0hm resistor instead of a 47-0hm resistor in the R3 position. The infrared LED array on all three boards lit up at expected. Immediately the R3 and R4 resistors became very hot to the touch, but this did not cause any observable problems. For the next five days I checked the boards once in the morning and once at the end of the day and they remained lit up. On the evening of the fifth day, I was checking them to make sure they were still lit up -- which they were -- when I decided to see if the solder on the R3 and R4 resistors was getting hot enough to melt. I checked if the solder was at all soft by poking it with medal tweezers while the boards were still plugged in. Before I realized what I was doing, two of the boards shorted. I did not notice anything when I touched the first board with the tweazers, but there was clearly sparks when I touched the R3 and R4 resistors on the the second board. The two boards, which had been lit up a moment earlier, were now dead and did not respond to commands from the LWDAQ Diagnostic tool. The third A2052 board was not touched by the tweezers and counted to remain lit until July 17 at 3PM -- nine straight days -- when I shut it off to leave for vacation. -alex