Need help identifying/replacing driver

Hi all, I need help identifying this driver or suggest replacement (if any).

It’s my friend’s flashlight, a Sea Dragon Mini 900 Dive Light powered by single 18650 and has side switch.

Mode sequences should be High - Med - Low - Disco - SOS, but when I checked, it’s Dim - Dim - Dim - Disco - SOS. I know it’s broken but I’m not smart enough to find the problem in the driver. I can only think about driver swapping.

I’ve checked the LED, replace it with other LEDs but the problem persists.

Driver diameter

Driver top

Switchboard top

Switchboard bottom

I’ve contacted the manufacturer/company, asking about the problem but they can only advise to send back the flashlight to their technician which is not available in my country.

Any help/tips would be very helpful. Thank you!

this look to me like some sort of buck or buck boost board (round), because the light take in one 18650 or two CR123. The rectangle board is for switch and Attiny microcontroller. It seem like maybe part of the connection to the switching driver (round) may be bad. If the SOS and disco mode work, the microcontroller seem to be working. Unfortunately difficult to debug without oscilloscope.

It sound to me that you can easily replace with an online driver of 22-23mm. If you just use single 18650, there are many driver available with lot of modes and BLF firmware since your LED is only a single XM L2 LED.

Cheap driver with sideswitch: https://www.aliexpress.com/item/5-Mode-1Mode-Input-3V-15V-dc-22mm-LED-Driver-For-Cree-10W-T6-XML-T6/32801253961.html

Lexel seem to have many driver, maybe you can contact lexel.

This was my main suspicion because I’ve had the same experience with Manker U11 (Quinlan). After desolder and resolder, it didn’t cure the problem.

Thanks, I think buying replacement driver is the best method.

Update:
Last night was my lucky night.
I try to resolder this resistor and it broke into two pieces without too much pressure!

According to the number on it, the resistance was 0.075 Ohm so I just by-pass it using a wire.

Now the flashlight has resurrected.