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help identifying a semiconductor

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Hi guys, i'm new here. Great site you have.
I'm having a little trouble locating a cross reference part or data sheet for a couple transistors.
Here's a little history if applicable:
I'm building a CNC machine, and i'm trying to repair the tool changer. I think i have traced the issues down to a transistor, or possibly all 3. I am limited in my electronics knowledge, but understand some basics, although i'm self taught.
Here's the part numbers:
f2n 4124 and f2n 4126. One is an NPN and one is PNP i believe. I can look later to see which one is which if needed. The board is circa 1980. Let me know if there's any more information needed. I have googled it, checked tons of sites, and still no info on it.
Thanks in advance!
i think the rectifier is bad. it's a SCR. It measures about 55m ohms across the anode, cathode, and gate, no matter what direction i go. Seems fishy to me. Found some online, trying to find it locally now.
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yay it's all working. weird setup. apparently one coil on the impact gun gets ac current and the other gets dc, which gets it's polarity reversed to change direction. all this time i thought it was all ac. swapping the SCR fixed it.
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