There were many users of Tmall's magic box before, and the remote control of Tmall's box was particularly costly. Find the reason today.
Judging from the number of posts, the number of remote control battery charges should be considered small compared to the total number, but it is by no means a single case. Since it is not a case, it should be a common problem.
Since most of the problems do not exist, there is no problem with circuit design. From the perspective of my remote control, the measured resistance between the positive and negative electrodes of the battery is relatively small, which may be a failure of internal components.
Based on this consideration, take a look at it. Here is the circuit board:
After checking the circuit, it is finally confirmed that there is a problem with the capacitor C15:
Test removed C15:
Such a small-capacity DC resistance should be in the mega-ohm range, which is obviously bad.
This filtered capacitor becomes the culprit for leakage.
The degree of failure of this capacitor is different. The DC resistance is different and the leakage current is not the same. This also explains why some days have leaked, and some have leaked in one or two months.
There are other filter capacitors, there is no problem with the C15. In fact, during the test, I also removed the C16, tested it and got no problem, and was too lazy to solder it back.
Since C15, C16, C17, and C18 are all filter capacitors, it cannot be judged that they are all C15 problems.
If there are a few more cases of C15 failure and no other capacitor failures, then it can be determined that at least one batch of C15 purchased by the manufacturer has a problem.
Judging from the number of posts, the number of remote control battery charges should be considered small compared to the total number, but it is by no means a single case. Since it is not a case, it should be a common problem.
Since most of the problems do not exist, there is no problem with circuit design. From the perspective of my remote control, the measured resistance between the positive and negative electrodes of the battery is relatively small, which may be a failure of internal components.
Based on this consideration, take a look at it. Here is the circuit board:
After checking the circuit, it is finally confirmed that there is a problem with the capacitor C15:
Test removed C15:
Such a small-capacity DC resistance should be in the mega-ohm range, which is obviously bad.
This filtered capacitor becomes the culprit for leakage.
The degree of failure of this capacitor is different. The DC resistance is different and the leakage current is not the same. This also explains why some days have leaked, and some have leaked in one or two months.
There are other filter capacitors, there is no problem with the C15. In fact, during the test, I also removed the C16, tested it and got no problem, and was too lazy to solder it back.
Since C15, C16, C17, and C18 are all filter capacitors, it cannot be judged that they are all C15 problems.
If there are a few more cases of C15 failure and no other capacitor failures, then it can be determined that at least one batch of C15 purchased by the manufacturer has a problem.