I have this chip and i wonder if it's broken, there's a little notch on top.

 

I don't see a notch.
No, I don't think it is broken.

 

 

How deep is the notch?
I could be purely cosmetic.

 

It's not cosmetic

 

Looks to me like a relatively shallow chip and should not affect performance. How do you know it is not cosmetic?

Edit: My use of "cosmetic" is the same as DickCappels description, post #8.

 

because new ones don't have that

it's not the bottomleft corner, look at the second picture

 

Here the term "cosmetic" means it affects appearance only, whether added intentionally or by accident.

The tiny chip is unlikely to affect performance.

 

Chips I've seen that have blown out typically have a much bigger crater. I tend to agree this is merely a cosmetic issue where the manufacturer may have had an air bubble in their carrier epoxy mix resulting in a shallow divot in the surface.

If the component had a blowout it would likely (but not necessarily) have sharp edges. I'll look through my pile. I have a UPS inverter with a blown chip. If I can readily find it I will take a picture of the blowout. It's fairly big.

[edit] if the flaw is deep enough to expose the electronics to any infiltration of light then it's likely the component will not work. If you recall UVEPROM's (Ultra Violet Erasable Programmable Read Only Memory) they have a glass window. Prior to programming they are covered with a metalized tape with the programming printed on them. The program can be erased by subjecting the electronics within to UV light. Or you could place it in the sun for a few days to erase it. Light can affect how the chip performs.
{end edit}

 

If it works...it's not broken.

 

Late, but as promised: You can see the devastation that occurred when I touched my meter to the wrong point. Also note the sharp edges as often occurs when chips explode. When this one went it went with a loud bang. Also, just for fun, notice the large heatsink it's connected to.

I could replace that component if I knew what it was, but with much of the face evacuated I have almost no hope of defining exactly what it was. There's a similar component directly behind it. Maybe it's the same part number, maybe it's a complementary component, sort of like one side is NPN and the other is PNP. Nevertheless, there's good chances when this went bang other things got hurt in the process. I could be throwing good money after bad. BTW: This USED to be a UPS.

 

Does it work?

 

Does it work?

Is the right question - I've seen internal eruptions "disappear" a bit of the encapsulation like that once or twice. Cosmetic defects like that are rare - but not impossible.

 

Does it work?

It stopped working, hence the reason for probing about, which resulted in catastrophic eruption of the casing. The chip mentioned that is adjacent but opposite both share the same negative power plane. The positive plane is guarded by two parallel 40 amp fuses. I guess they couldn't find an 80 amp fuse ? ? ?

Replacing that blown chip will likely not result in making the unit work again. It's probably best left for scrap materials such as the latching push button switch, the 15 amp 120 VAC breaker, the surge protection circuitry, and whatever else can be pulled out of there.