What transistor do i need?

Thread Starter

Howellm2

Joined Apr 27, 2018
6
Hey guys this is my first post so go easy. I was mucking around putting an argon solenoid into my welder and when i was testing some voltages i shorted a transistor.

Anyway...

I need some help tracking down what type of transistor i will need. The old transistor has some very difficult to read writing on it and that is as follws;

A2318 EJK25

And the welder itself is a BOC SmoothArc Multi Process 175

I’m hoping that the writing on that transistor means something to someone out there or that someone somewhere has seen this type of PCB before.

Thanks in advance for any advice or help.
 

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dendad

Joined Feb 20, 2016
3,032
I wonder why you were "mucking around" with the board in the first place. Was there a problem?
That is some sort of integrated circuit. What makes you think it is dead? Was it cracked?
It looks to be a switch mode power supply.
Is there any labeling on the other side of the board to show voltages?
If you clean the board area a but with isopropyl alcohol on a toothbrush, and take some closer pictures, both sides of the area, a circuit may be drawn to try to identify the part. It is a bit hard to see where some of the tracks go.
It may be...
https://www.sparkfun.com/datasheets/IC/MC34063A.pdf
Wired as fig 10.
But do not be surprised if the board is now DOA buy feeding the wrong voltage to the rest of the circuit.
 
Last edited:

Thread Starter

Howellm2

Joined Apr 27, 2018
6
I wonder why you were "mucking around" with the board in the first place. Was there a problem?
That is some sort of integrated circuit. What makes you think it is dead? Was it cracked?
It looks to be a switch mode power supply.
Is there any labeling on the other side of the board to show voltages?
If you clean the board area a but with isopropyl alcohol on a toothbrush, and take some closer pictures, both sides of the area, a circuit may be drawn to try to identify the part. It is a bit hard to see where some of the tracks go.
It may be...
https://www.sparkfun.com/datasheets/IC/MC34063A.pdf
Wired as fig 10.
But do not be surprised if the board is now DOA buy feeding the wrong voltage to the rest of the circuit.
Thanks for the reply mate. I measured the voltages on the tracks going to the transistor but I’m not sure what pins are what...
 

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dendad

Joined Feb 20, 2016
3,032
I think you could try the MC34063A but there is a chance the rest of the board is dead because of incorrect voltage being applied.
You did not say why you thought the original IC is dead.
 

Thread Starter

Howellm2

Joined Apr 27, 2018
6
I think you could try the MC34063A but there is a chance the rest of the board is dead because of incorrect voltage being applied.
You did not say why you thought the original IC is dead.
Oh it was smoking the led next to it turned off
 

Thread Starter

Howellm2

Joined Apr 27, 2018
6
Did that happen when you were probing around or was there a fault before?
It is hard to advise you. Try a replacement chip but be prepared to have to get a new board if you can.
It happened when I shorted it out when i was ‘probing’ haha. Sweet ill try that chip bro and if it doesn’t work ill just get another board.
 
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