Repairing a Bicycle battery

[fant]

Good morning;

I am trying to repair a BMS for a bicycle battery where a component is missing.
Anybody has the same board so to know the characteristics of the component or at least a datasheet of the protecting IC (OZ7714CN)?
The open voltage of the battery is 48V, but no power on output.

 Thank you in advance

[Greybeard]

Datasheet:
http://www.o2micro.com/products/O2%20807&G807C%20Product%20Catalog%202023-6-26(final).pdf

Problem:
Your IC is SOIC24, datasheet shows QFN28, so pin numbers are not matching.

[fant]

Good morning;

thank you for the link, but I had already seen it and discarded due to the pin count difference.
I can find some spare on aliexpress, but before changing it, I would like to make some circuit investigation.
 Anyway, again thank you for the search and time spent.
If anybody has new info, will be very appreciated
Best regards

[indeterminate]

At a wild guess it will be the Bat 1 pin of the ic so the missing component will be another 100 ohm resister

[fant]

Thank you "indeterminate".
I did it, but it begun to heat up.
Tested, the voltage difference between pins is 3,7 - 3,8 V (probably the firs element of the battery pack), so I've tried with a 0,1 uF and second test with a 1 nF capacitor, but no result.

I am beginning to think that that it is locked into the anti-theft function, even if the battery belongs to a friend of mine and therefore I know that the origin is legal and he assured me that there is no switch or key on the battery for this function.

Continuing to dig.

Thanks to everybody

[Greybeard]

This photo may help you (arrow doesn't mean anything):



https://electrotransport.ru/index.php?topic=5439.msg2302542#msg2302542

I would not invest much time and energy to find the root cause of your problem, I'd just buy a new BMS PCB.

[fant]

I made some more test, but no result.
So, probably I will buy a new BMS.
The deadline is Tuesday, If I will not fix it, I will change BMS.

Thank you to everybody for the suggestions and help.

Mandi