No 1st gear 4L60E help

[KINGBYNG]

Hey all. I've recently replaced the blown trans in my 93 K1500 4x4, with a cheap used replacement, acquired in a private sale.
The previous owner claims (and seems quite honest) that this used trans worked properly when pulled, and had about 250,000KM on it. The fluid inside was nice and clean, and I decided to use the old torque converter that came with it.

Since installation, I've only taken 1 short drive with the truck, and it definitely doesn't go into 1st gear wether I put the shifter in 1st or drive. I wasn't able to go fast enough to see if it would go into overdrive but 2nd and 3rd are definitely good.

I'm planning on taking it for another test drive to see wheather overdrive works, if it doesnt then I'll swap shift solenoids with my old trans.
Is there anything else I could have missed during installation, or anything else I should check to figure out why no 1st?

 

[tayto]

what year was the replacement from?

 

[1997]

diagnosis would be more accurate, if you post tayto's requested info ..........

OBD1 can set codes without check engine light coming on, any codes?
sounds like it's in "limp" mode.
when you shift from park or neutral into drive/reverse, is it a "hard" shift?
if fuse #20 in the driver side interior fuse panel is blown, it can cause your sympton.