ESP8266 Community Forum

I just got some D1 Mini 12F's to compliment my supply of NodeMCU 12E's. I am noticing that the minis have much cleaner construction, and the NodeMCUs seem to have some of the traces ripped off.

Has anyone else noticed this on your own chips?

What would cause this to happen at the factory?

I have seen this on many modules. Once frequently on a NEO6m GPS Modules that we were using in a project. We used to get lots of 100 modules in our office and remember few lots were all like this. Happens when the right reflow solder/temperature is not used. Some cheap modules in China use salvaged chips. These chips have pins wil solder already on them(maybe with corrosion also) and when they try to reflow it, this happens.

Whatever the reason, it is poor QC. Even if these modules work, they may not be reliable. You dont know when they will stop working.

'PCB', right? These problems are quite common with low cost version of these boards. But doesn't really affect the functionality.