LED ID and tips for its driver transistor ID

Hi everyone, this is a refrigerator light system 36V, main power board with 4 LEDs, 2 additional slave boards with each having also 4 LEDs. Each board is running on 12V in series connection totaling 36V and 50 mA each LED if I am correct. Found tiny transistor burnt/shorted and 2 its related resistors burnt but still conducting/responding to ohm meter. I assume/guess that it has a constant current driver with soft start. 1 LED is damaged on 1 of the slave boards marked NR270U - 0 is in shape of football slanted 45 degrees. The LED’s lens is 5mm x 3mm and 5 pins, each corner one and in the middle, 2 pins are connected together, couldn’t cross-reference it yet and I tried. All other LEDs are good tested by ohm meter and they produce dim light. I replaced the shorted transistor and replaced burnt resistors 91 and 127 ohms. The closest I found in my supply was 100 ohms for the burnt 91 ohms and 13 ohms for the burnt 127 ohms. Electrolytic caps were still good. I had only the main board with 4 LEDs so I hooked to the output connector 250 ohm resistor advised by youtube clip as a dummy load to test it. It comes on but the light intensity is about 1/3rd and the voltage on the 36 volts side is only over 1 volt. If I leave it running little bit longer, some of the resistors I replaced starts to smoke so I turned it off to find the culprit. Other semiconductors like diodes and transistors tested good so I am thinking about the perhaps mosfet driver its self but not sure. The boards have what I think is a LED diode protectors PL18 if I am correct.
One of the slave board is marked as 11V-14V 200mA which would suggest total of 600mA for the light setup requirement.
The driver transistor I tested good but perhaps under load due to getting 120V dc maybe not responding correctly after the torture short of taking it out and test bench it. Marked as ON (firm) RMB 1014B, package SOT 223. I and my electronic store tried to cross it to N.A.
I would like to find how these drivers function so I can educate my self so I would be able to fix them. I have just basic comprehension of its current limiting for these LEDs but I would like to go to details and so far I couldn’t find more specific guide on the web and tube.
A guide how to properly match driver for set of lights can help me even just to pick a small drivers on the web for a few of bucks and modify the main board so I don’t have to deal with this issue but I prefer to fix the existing main board so I can learn and perhaps to modify the current to little bit of current less by changing some resistor so these LEDs wouldn’t be at full speed. There is not too many components so it should be easy to fix it but matching and cross-referencing of these parts is a cookie to me now.
Thank you for looking and responding.

Thank you for your inquiry and welcome to the TechForum. I am unable to cross the part given . You might want to check with the original manufacturer to see if they will offer you a replacement. If they purchased enough, the part may have been marked for the application specific for the manufacturers bill for materials.