Open sprinkler 2 SM

[djdan]

Hey Just got the new version 2 looks nice as!

I purchased the DIY version, Cant wait to get it going!

I have a small issue with mine, I can get it to work on USB, Powers up however it has blown the fuse on the 24volt side. I replaced the fuse with the same outcome.

I cant see any solder bridges, and have been looking at the schematics, where it appears most of that circuit is SMT.

So im a little lost when else to check.

Open to suggestions, thanks in advance.

Dan

[Ray]

Hmm, if I understand correctly, you mean the fuse is blown when you power the controller by USB? Since the fuse is on the 24V AC line and not on the USB power (5V) line, I can’t think of any obvious reason why this would happen. Did you measure the resistance between VIN-GND, as well as VCC-GND? What are the resistance values you are getting?

[djdan]

Hi Ray,

The Controller works correctly on USB.

However when powering from 24Volts, with Nothing else connected. it blew the fuse.

I measured those and they seem normal. (From what others have posted.)

I must be missing something…. or The 5volt regulator or diodes are shot?

[Ray]

OK, that’s good to know. I suggest doing the following:
1. Measure the resistance between VIN-GND again, and the value should be somewhere around 4.5Kohm to 9Kohm. If it falls below 4Kohm, it’s likely that either there is a short somewhere, or a component is burned (most likely the zener diode, or the LM2596 switching regulator).
2. If the resistance is correct, then something on the 24VAC input line is shorted. There are only a few components on the 24VAC line (fuse, diode D1, capacitor C1, LM2596, so it shouldn’t be too hard to narrow it down.

[Ray]

Coming back to this thread: it occurred to me that it could also be that the fuse just got broken due to mechanical reasons. As long as the VIN-GND and VCC-GND resistance values are acceptable, you can replace the fuse with a wire and test again. If you need a replacement fuse, contact [email protected] and we can arrange to send you a replacement fuse.

[Author]

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