Can't locate replacement transistor for obsolete A317

This is from the control board of a 1986 Century 160 amp MIG welder. I can't seem to find a replacement part number anywhere. Can anyone suggest what might work to replace it? Thanks...


Thank you for contacting The Digi-Key Technical Forum. I am sorry. I was no able to locate any data on this part number. It must be a Fairchild semiconductor part per the F . I just can’t identify it. It is either to old and no longer made , or it might be a custom part. Unfortunately without any data, I am unable to verify the part number anymore as active.

Hello @zx750turbo,

The UA317UC Fairchild part crosses to an NTE956. Based off of the NTE specs, any LM317T Linear Regulator in the same package should work. Please see the possible options here.

That’s the problem, it has become obsolete, but surely there has got to be another one made that functions the same with specs close enough to work you would think…

If data on it is what you need I can supply that, I found the data sheets on Google.

Fairchild-A317-datasheet.pdf (52 KB)


I see that Jeff offered a link to some part numbers that should work. You can look at part number LM317TGOS-ND as an option .

Yes he did, thank you very much for the information it was a lot of help to me thank you very much.

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