Identify a cracked component (diode?) - "8CBB"

I am looking for some help in identifying a component. The component is my son’s electric guitar foot pedal, the pedal doesn’t power on at all, the power source is a 9 VDC power supply, (tip negative). There appears to be a cracked component right at the power input, I can’t identify what it is and I haven’t been able to get the appropriate help from the manufacturer. The only markings on the component are “8CBB” and I believe it to be a diode. Here are some pictures. Any help in identifying a replacement component would be greatly appreciated.


I am sorry I can not ID that part marking.

The marking of “U1” means that the part should an integrated circuit.

Given the package style (three pins plus heat sink tab), and that it is on the edge of the PCB, I suspect it’s a 3 terminal linear regulator.

Also, when a linear regulator explodes like that it usually means many other parts will be damaged to some extent. Some of the other parts are likely outright dead, others will be weakened and may die at any time during future operation. So if your son is using this live on stage it would be wise to replace the whole PCB assembly, or device, so it doesn’t quit in the middle of a show 6 months after it’s repaired. (this was my common advice to guitarist friends whose foot pedals were relatively inexpensive essential musical instruments used to earn money)

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Hi @canuck88 ,

Thank you for reaching TechForum. Agreeing with PaulHutch, it is most likely a regulator with the TO-243AA (SOT-89-3) package. Since the input is 9v I would venture to say it would be a 5v regulator. When you said this cracked chip was right at the power input, my initial thought was the power plug got stepped on when on-stage causing the chip or board to crack. However, the PCB looks fine and the chip definitely looks blown based off the photos.

Regulators are fairly robust components as they usually have failure mechanisms and it is rare when they blow-out like this. One could assume that a wrong, higher-voltage power adapter was used. Hopefully the regulator protected and opened before damaging other components but that is an unknown.

If you want to gamble on a possible replacement, and going along with the hopes that the rest of the circuit is functioning, you may want to try below component, but you may want to verify the product is not under warranty before doing so.

Click here for Diodes Incorporated 31-AZ1117R-5.0TRE1CT-ND.

image

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I think I’ll try the regulator you mentioned, thanks for the advice!

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