Help identify component on vsett display board

[dalle3]

Hi, I'm struggling to find what this part is , the board not powering on anymore it is the only part that gets hot when power on button is pressed
It should be transistor 3kvf

Cheers

[R_J]

The logo is for Microne (Nanjing Micro One Electronics Inc.) It is marked as D2 but it may be a voltage detector? Microne does not provide top markings in their datasheets, If the component is defective, you might be able to contact them for information.

It might be a LDO similar to a ME6231 which has pin1 ground, pin3 Vin and pin2 Vout, so there may be a shorted cap or component on its output causing the ldo to get hot?

[dalle3]

Thanks, have searched but sadly nothing more found 😔

[truclacicr]

7533-1 is a 3.3V LDO regulator. Its 5V input goes to pin #2 of D2.

http://www.e-ele.net/DataSheet/HT75XX-1.pdf

5V++ is the output of a switchmode DC-DC converter. It goes to pin #3 of D2.

Pin #1 of D2 is grounded.

Therefore, D2 could be functioning as a power switch or ideal diode, or maybe a current limited load switch.

"WE" is a 5V TVS diode, so the output of the DC-DC converter is protected from overvoltages.

https://www.vishay.com/docs/88390/smaj50a.pdf

[dalle3]

Thank you truclacicr perfectly explained, now i can order part 😃👍

[adam7]

dalle3,

It is 3Kxx, 3KPE - ME6216A50XG.
https://jlcpcb.com/partdetail/497219...6A50XG/C487910

[truclacicr]

ME6216A50XG is a 5V LDO regulator. That is, a 5V regulator with a 5V input and a 5V output.

I don't get it. :-?

[adam7]

Hi, truclacicr.
This is a translation of the datasheet from Chinese to English.
It has an output voltage of Vout=3.3V.

High-precision output voltage: ±1%
Output voltage: 1.0V~5.0V
Maximum operating voltage: 6V
Very low static bias current (Typ.=6.0μA)
Strong load capacity: When Vin=4.3V and Vout=3.3V
I out=300mA
Very low input-output voltage difference:
110mV@ IOUT =100mA 240mV@ IOUT =200mA
Good input stability
Can be used as a regulator and reference voltage

[lotas]

But the case here is not SOT23, but SOT23-3.
Check the resistance between pins 1 and 2, if it is low, then most likely the controllers are faulty.

[lotas]

And is there also a connection between points 1 and 2?

[truclacicr]

adam7, your link points to an ME6216A50XG with a marking of 3KPE. That's a 5V regulator, not 3.3V.

I wonder if the designer is using a 5V LDO regulator as a current limited switch.

In any case, the output of the regulator is marked as "5V' on the PCB, and the input is "5V++".

[lotas]

It's not clear yet, maybe it's powered that way.

[dalle3]

Thanks for helping me out, I was on short trip will be at home and check tomorrow

[dalle3]

But the case here is not SOT23, but SOT23-3.
Check the resistance between pins 1 and 2, if it is low, then most likely the controllers are faulty.

Have checked resistance is 2.0 ohms

[dalle3]

And is there also a connection between points 1 and 2?

Yes they are connected no resistance

[lotas]

Well, 2 Ohm is bad (short circuit), it could be ceramic capacitors and the controllers themselves, here you can supply 3v from a laboratory power supply to this bus and see what will heat up or cut the track on this line and check where the short circuit will remain, on which side...