Hello everyone,
I found an old mini r2 that doesn’t work anymore, most likely I missed some connection. Opening it I noticed that a resistance jumped but I can’t figure out how much it’s worth to try to replace it. Can anyone help me?
This is not a difficult repair. It needs to be replaced piece by piece.
I know it’s not difficult but I don’t know what that exploded resistance is to replace it
Hi, I had the same problem. That green capacitor needs to be replaced. It’s inexpensive 
it’s not that simple.
Something caused it to fail in the first place,
These modules often use transformerless power supplies consisting of a capacitor to control the AC current, a zener diode and bridge rectifier.
Transformerless supplies often fail and are a cheap substitute for transformer supplies.
The resistor has got very hot, but once out of the circuit, you might be able to measure it.
The components on the resistor side are all cheap, but whether it’s worthwhile is debatable. You might find that other things have failed. Removing components from double sided PCBs isn’t easy and can damage pads and tracks.
I just wanted to understand, first of all, the exact value of the resistor labeled R9 on the board, so that I can replace it. Since it appears to have ‘blown’, I can’t read its value correctly
@MichaelLearnsToCode can u help me?
Sure, I’ll contact SONOFF staffs who I know to see if they can be helpful here. I should be able to get back to you within 48 hours.
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That resistor is protected by heat-shrink tubing. It might be burnt because the blue varistor that protects against overvoltages is short-circuited. If so, replace the varistor first. I just opened a mini-microphone with a similar circuit in that section, and I couldn’t read the resistor’s value because of the heat-shrink tubing. It seems that the function of that resistor is similar to that of a fuse.
**We strongly advise against attempting to repair or replace any components yourself.** Any improper handling could lead to potential hazards, including short circuits or damage to other parts.
To ensure your safety and a fully functional product, our support team has already arranged a replacement unit for you. The new device will be shipped to you shortly, and we hope it serves you well.
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