Chip identification

[Shush]

Hi, I'm a novice with an interest in electronics, because Ive had some success repairing things a family member has given me a dead board to look at.

I found several shorted components about one of them has me stumped as I can find nothing about it anywhere, it's marked BCEOD and is U1 in the picture.
I would be grateful for any and all help to identify this chip.

[DavidAlfa]

RY8120

[pcprogrammer]

RY8120

Oops you did it again. Hooked into another thread

Oh dammed so did I

[pcprogrammer]

Looking at the marking it might be BCE0D. So a zero instead of an O.

Not sure if the RY8120 is the correct one, because the marking is BC, year, lot number code.

For BC marking in sot 26 I found this one https://www.s-manuals.com/pdf/datasheet/r/t/rt9010_richtek.pdf

[DavidAlfa]

that's why I'll be making davidalfa 2,3,4,5,6... usernames soon

Yes but this is a switching regulator, not a LDO, check L1!
The bootstrap capacitor C3 seems to be going to pins 1&6, L1 to pin 6, R2/R3 feedback to pin 3, everything matches.

[Shush]

Thanks for the input guys.

It is a voltage regulator but there’s only 2 pins with voltage and they’re both at 12v which is the same as the input voltage to the board, every other pins shows a short.

I’ll take a look at the part that’s been mentioned and go from there.

[pcprogrammer]

Make sure to verify the circuit with example given in the datasheet. Most often you can match up that way when more then one type of component is found based on the SMD marking.

Edit: With the 12V being the input voltage and seeing it on two pins might mean that it is shorted internally and the 12V killed more components on the board.

[DavidAlfa]

R2 has a suspicious black line on it, could be cracked.
Those resistors use EIA-96 marking.
Don't measure them in-circuit, desolder one side and slightly rotate it so one side becomes isolated.
05D = 100K
18C = 15K

If broken, the controller feedback might read 0V, setting the output to 100% and blowing everything up.

The resistor ratio is a bit strange:
0.6*(1+(100/15)) = 4.6V

What are those wires instead L1?
You cannot measure the voltage without it, all you will read is 12V spikes and kill everything connected to it.

[mariush]

You should also reflow the components around the chip ...  solder on tops of C1 and C2 don't look so good to me, and I'd reflow the inductor and the ceramic capacitor right to the right of the U1 chip.

[Shush]

Hi guys, an update on this.

I ordered the chip as advised and reflowed the resistors, they were giving the correct readings so I reused them.

Just fired it up on my ben power supply and its working.

A massive thanks to everyone that commented, it's very much appreciated.