|My Minima Transceiver Modules|
This photo was taken at Salmoncon 2014,
Thanks to Linda - AB7YL
My Minima CPU Board has Died!
The voltage on the 5.0V Rail was measured at 7.8 Volts. The regulator was fried, which I am sure that voltage cooked the ATMEGA328P-MU Microprocessor as well. I knew the regulator was under rated for the increased load that I had put on it, but it had worked so far, even though it would get very warm.
The Attempted Repair
For repairs, I first replaced the 5 Volt Regulator.
Now the 5 volts Rail is correct, but the microprocessor is still toast!
My attempt to replace the microprocessor was NOT so successful, some traces were damaged while removing the micro. The micro had been solder through the back side of the PCB as a heat sink. De-soldering the heat sink heated the board and small traces TOO much, damage was almost inevitable. In hindsight, it would have been better to Hot Air reflow the part off. But I do not have Hot Air tools.
This of course is one of the pitfalls of using very small quad-flat-pack version of the microprocessor, if it were the large DIP, replacement would be a quick chip replacement. But, I like to use the smallest chips that I can find.
My software modification testing will have to wait until I replace the board, but I am NOT looking forward to re-building this Homebrew board with its 85 via's.
I decided to pay the bucks, and have OSHPark.com manufacture a set of boards for me. The boards will be in hand in about a week. I will continue working on the Minima Software additions, but software testing will have to wait.
Maybe, this may provide time for me to finish my Homebrew Audio boards for the Minima.