Unidentifiable

[keyboardcowboy]

Sorry for posting in the wrong section



can someone help in identifying this transistor type thing, it has no markings on it or on the pcb from where it came, its fried (short on all pins)..
came from a NOKIA AC-4E charger

[stj]

Re: Unidentifiable

impossible to id from the shape.

[ratdude747]

Re: Unidentifiable

idk either. i fried one trying to add a heatsink (in a mad catz 3v car adapter)... they overheat quite often...

[NxB]

Re: Unidentifiable

My guess is a voltage regulator since it came from a charger. Without a pic of the circuit or any markings there is no way to say for sure.

[stj]

Re: Unidentifiable

most nokia stuff is switching, not analog though.

[keyboardcowboy]

Re: Unidentifiable

Here's the Original circuit

[kc8adu]

Re: Unidentifiable

likely any npn power transistor will do.
its a crude simple switcher.

[keyboardcowboy]

Re: Unidentifiable

Any recommendation?

The charger is rated as 5v/890mA

[stevo1210]

Re: Unidentifiable

Um. I don't think a new charger would cost much...?

[keyboardcowboy]

Re: Unidentifiable

Well its not about the price, this charger was just lying useless, just wanted to get some experience in repairing stuff

[Wizard]

Re: Unidentifiable

Remembered the design like in ultrasonic circuit just one transistor and oscillator using R & C circuit in 60 Hz bursts in KHz range (around 30-50KHz). Use a NPN with strong voltage tolerance and high base voltage tolerance as well. Not too critical.

Cheers, Wizard

[NxB]

Re: Unidentifiable

Open a similar charger up and see what they used.

[delaware74b]

Re: Unidentifiable

I zoomed in on the photo on the solder side of the board and it looks as if pin #2 (center) has been partially lifted from the board.

[370forlife]

Re: Unidentifiable

I zoomed in on the photo on the solder side of the board and it looks as if pin #2 (center) has been partially lifted from the board.

it may be still usable or just remove the lifted part of the trace and run a wire.