Aquarium led lights ,Transistor Identification

[ntec]

Hi, I'm repairing my expensive aquarium led lights and need to replace a broken sot23 transistor. I need help in identifying the correct part to order for replacement. I have attached the pic showing markings of B28W and the transistor sits beside a 0 ohm resistor and a capacitor.

[R_J]

Re: Aquarium led lights ,Transistor Identification

What makes you think U1 is defective?
Another site with the same board thinks it is a single wire epprom like the microchip 11AA020
I doubt the component is the problem as it doesn't seem to be connected to the actual led's, they drew a diagram:

A closer look and it seems D21 & D22 could be bad

[ntec]

Re: Aquarium led lights ,Transistor Identification

[QUOTE=R_J;1178310]What makes you think U1 is defective?

When I looked at it close up it appears to have a burn mark on it and there is a short to ground on the leg. When I checked with my other working board there is no short.

[petehall347]

Re: Aquarium led lights ,Transistor Identification

remove it and see if short has gone

[ntec]

Re: Aquarium led lights ,Transistor Identification

remove it and see if short has gone

I removed the chip and now where it was shorted now doesn't beep on my meter, just shows ol. The problem now is trying to determine what type of chip this is to find a replacement. I still have my old led boards that still work fine, the one in the pics is of the newer led board that I bought off someone and trying to fix as they are better. So not sure if there is any tests I can do with my old functioning led boards to try and determine the type of chip it is.

[redwire]

Re: Aquarium led lights ,Transistor Identification

What make/model aquarium lights are these? Ecotech Marine Radion XR32 I did not find.

I agree it is likely a serial "UNI/O" EEPROM chip (11AA020) that holds some saved config or calibration for LED brightness info etc. You'd have to copy the contents of a good one into a new blank IC. Hopefully there is nothing extreme like a serial number paired to the main board.

Check the MCORE PC board the LED's are mounted on, has not shorted. There is only a thin film between the aluminum and the traces. These aquarium boards frequently get water damage on them.

[ntec]

Re: Aquarium led lights ,Transistor Identification

[QUOTE=redwire;1178625]What make/model aquarium lights are these? Ecotech Marine Radion XR32 I did not find.

It's the ecotech radion xr30 g4. One thing I forgot to mention that may help identify part, is on my functioning led board that chip is labelled B2Y7.

[R_J]

Re: Aquarium led lights ,Transistor Identification

This means that the B2 is likely the part number and rest is date code or mfg. info.
Do you know how and where it is used in the circuit? is it actually connected to the led string? Do D21 & D22 look the same on the working board?

[ntec]

Re: Aquarium led lights ,Transistor Identification

Yes D21 and D22 look the same on the working board. Here is a video of one being taken apart. The Led board i'm trying to fix is the pro version led board which has more leds on it then my old non pro ones so maybe that could be why the markings are different as whatever that chip does has to power more leds but who knows. https://www.youtube.com/watch?v=2BiY...hannel=FixReef

[ntec]

Re: Aquarium led lights ,Transistor Identification

I agree it is likely a serial "UNI/O" EEPROM chip (11AA020) that holds some saved config or calibration for LED brightness info etc. You'd have to copy the contents of a good one into a new blank IC. Hopefully there is nothing extreme like a serial number paired to the main board.

Hmm I had another person tell me that it could be a single line eeprom chip. I tried searching and could not find anywhere that sells a single line eeprom programmer that can program a small sot 23 chip. I've seen eeprom programmers before but never one that can program a small chip like this.