Hi,

Can anyone inform me what this component is? And maybe point me to a replacement? It is located on the control board of a bathroom ventilator.

 

What makes you think something's wrong with it? Oh, I see the burn now.

 

What makes you think something's wrong with it?

Smoke coming out of it due to reversed 12v polarity. the fan works, but the control unit is dead, so the fan either runs or it don't. I'm pretty sure this component is the key, whatever it is..

 

The burn mark looks like it's destroyed the last digit. It's probably a 2SB1110,1112,etc. Do you know make & model of ventilator?

 

What makes you think something's wrong with it? Oh, I see the burn now.

Yeah.. pretty annoying. And can't find it on Google by the numbers written..

 

2SB111X series come up as PNP transistors with 1A to 3A rating. If you can confirm it's PNP by using an ohmmeter on a hopefully good junction (EB, BC) I'd go with the highest amp transistor.

 

2SB111X series come up as PNP transistors with 1A to 3A rating. If you can confirm it's PNP by using an ohmmeter on a hopefully good junction (EB, BC) I'd go with the highest amp transistor.

I'll look into that. Thank you very much!

 

i don't think it is a transistor. silkscreen next to it clearly shows IC1 so this is an integrated circuit.
picture of entire board from both sides would be helpful.
if failure was caused by reverse polarity, chances are that this would be a voltage regulator for example.

 

A bit of reverse-engineering to trace the nearest half dozen or so components connected to the IC might also help for identification.

 

Thank you for your help everyone. I'll dig further into this.. see if I can figure out if it's one or the other. Your help is appreciated.

 

All of those capacitors next to it suggest it may be a voltage regulator (VR). They are usually not very tolerant to reverse voltage. Voltage regulators are often 3-pin devices with one pin connected to ground. The center pin of your device (tab) is connected to copper pours on the top and bottom of the PCB. That is for a heat sink, but could likely also be ground.

 

Probably a 3 or 5v regulator...

 

Probably a 3 or 5v regulator...

I think it's a 3.3v regulator. I'll try that.

 

It may be a 1117 reg?