Hi everyone,

Got to the “hook up the power” test. I’m using a Rainbird 26VAC, 700ma transformer off my existing irrigation controller. AC output measured 27.2VAC on a Fluke 8080 multimeter when the transformer was plugged into the power strip on my bench without a load.

After installing the battery, I installed two leads into Power In connector, turned on the power switch and immediately smoked IC1, the MC34063. 😮

There was a pop and smoke, the epoxy case is cracked between pins one and two on the MC34063. 🙁 IC1 is definitely toast…

Nothing else (IC or LCD) was installed per instructions. The IC1 was oriented properly, all the pins were seated in the chip holder. I’ve been going over the board as I build it with a magnifying headset looking for cold solder joint, solder bridges, etc.

Can you tell me where to measure voltages around the PCB without MC34036 installed to confirm operations and most importantly, where is a good ground for all my measurements?

BTW, the instructions are missing a step to install the rain sensor contacts (they are in the photo but missing in the instructions). Also, I was shipped three 220 uf electrolytics instead of 2 x 220uf and 1 x 10uf so whoever is picking your parts is messing up. I was able to get the 10 uf electrolytic locally so installed it & don’t need a replacement….