วีดีโอ

Try replace the external battery...

Try replace the main battery👍

Oh sorry i haven't check...let me know if this really important for u to know, i will open it back and check for you.

Am sorry about that, that was my mistakes when early started making videos...

Technically must minimal difference. However, multimeter able to measure specific area in the circuit that useful in troubleshooting.

@@elex5183 ah good point. Perhaps it's possible to use both at the same time. Thanks for replying to my question.

Thanks for the feedback. When using 2nd unit comparison, have to compare components reading with both same part number and the same location. If so, both circuitry should be the same. You might need to discharge first the points that being measured. This 2nd unit comparison is a very common method in troubleshooting. We have repaired hundreds of faulty pcb by using this method. But i agree that this method cannot detect 100% functional fail IC.

@@elex5183 thank you for your reply, i am working with electronics repair and as a hobby since i was a child, what i want to say is from all these years of my experience i founded that difference in resistance in IC pins that is still in board connected doesn’t mean that IC is damaged i founded in some cases a resistance changed value to high value and in another case i founded a capacitor which is connected betw. 2 IC pins make reading low resistance, and in some cases the cause is the board itself because its a multilayer pcb and make some damage in pcb layers 2 or more, the other components that should be tested is coils that’s available in transformers and as a coil alone, we use another way to test them we use the Q factor measurement way , this is done by a small device that can detect even if a 2 turns shortage inside coil , i have now 2 smps boards identical one is good and I found some different readings in board around Mosfet then I removed Mosfet and the IC s around but all was ok , all diodes and transistors are ok , still problem not solved , so this method may take a long time to detect faulty parts , practically i can not test all parts a hundreds of them , so the best and effective way is to use oscilloscope and take photos to each point and save it in laptop for a good board then use it as a reference, its useful even if you don’t have another identical board, you can see I/P and O/P signals in each IC or a microcontroller or CPU or memory.. etc , I liked your methods and its really useful but still can not solve all problems, and i want to thank you for your efforts to share us your experience, and i am a new subscriber to learn from you 🙏

Yes you are right...The point is, we have to start somewhere in troubleshooting...Finding differences between good and bad units reading are something good to start with...When u found mismatch reading on IC pin, u dont declare right away it's faulty...You need to validate it first...Most of the time we sketch our own schematic to understand further that area...But then again, i agree with your opinion...You have your solid experience as proof...We have our own...And we found this method useful, especially if we can power up the unit and do voltage checking/comparison...thanks

@@elex5183 best regards to you , keep making videos, i like what your videos content 👍

Trace the line of 5V circuitry and components involve. If the the failure occurred suddenly on normal operation or condition like no overloading or modification then it is most likely due to faulty electrolytic caps. Otherwise, focus on checking low ohm/shorted semiconductor components or IC(especially pwn IC). You can pls share the controller part number, let me check online how it looks and see how i can help👍

Thanks for the feedback...fixed that with my new videos😅

thanks for visiting madam😅

😁😁😁

Thanks for watching...when u buy something new it should came with usermanual that can guide u the installation. You can also contact the supplier and ask advice. I dont have ebike, I can only assume in this case, the K might be additional feature/function/option of the new board version. It can be an interlock too. Most likely you're right that K stands for keyswitch...Typically K in pcb stands for relay. I will try google it later, will keep u posted with my findings. Thanks

@@elex5183 thanks for replying. yeh, I got it off Aliexpress. no manual, no nothing. spoke with the vendor, actual response: "the PCB local "K" it's actually for temperature sensor, and you can leave it if don't need, it doesn't influence other functions". is this something you're familiar with or have heard of too? btw, it has gnd (-) through hole beside to complete circuit, jfyi. thanks again bro. /bklyn 👑

Oscilloscope for waveform, freq, amplitude of signals, the part must be powered up to measure...Huntron measure analog signature like resistance, conductance, capacitance at offline state...no need to power up the part when using huntron...Yes the huntron tracker can test IC (pin to pin check) and compare readings to good part...dmm also can use, i mostly used dmm than huntron...

Yes you were right, we have fluke thermal imager as well. Have tried it for this board when powered up at workstation. Unfortunately it does not give significant readings to help us locate the bad IC.

Just directly google the part number of IC.