Beginner Question - Repair of 8.4v lithium battery PCB

[brooko]

Hello, I have removed the PCB from a lithium battery used to power cycle lights. 8.4v 18650 8cells
I believe that the PCB is damaged as the lights on the power source won't stay on, but will for other battery packs.
Can anyone advise how I check the PCB please. The equipment I have is...

Bench power
UNI-T volts, amps and resistance meter

Pic attached
Thanks, Andy

[tunk]

Could be an BMS. Any markings on the ICs?

Edit: What's the voltage of the two cells?

[brooko]

Hi, thanks for looking at this.
The chip has 8205A Y105220F on it. The batteries are putting out 7.4v.
Andy

[SeanB]

Could be the one cell is failing, and thus the pack shuts off. Put it in, and run till it cuts off, and measure each cell block voltage. Likely one will be just under 3V when the BMS cuts off the pack.