Replaced broken digitizer. Now random numbers auto populate for pin.

Hi Brian,

As seen on another question, that kind of behavior has been observed when the digitizer isn't plugged into the motherboard, so it's possible it either isn't plugged in correctly or some pins in the connector got damaged.

Screen replacement causes lcd to go crazy? - iPad 9 Wi-Fi - iFixit

Unfortunately, the original author didn't come back and let us know how it all turned out, but your best bet at this point is to open it back up again and check the connectors. Use a magnifying glass and a bright light and check both sides of the digitizer connectors, looking for bent, broken or missing pins. Bent pins can sometimes be straightened with fine tip tweezers.

Assuming the connectors look good, check the cable for any tears or sharp bends. If everything looks good, clean both sides of the connectors with 90% or higher concentration isopropyl (rubbing) alcohol, give it a moment to dry, then reconnect and retest.

If it's still misbehaving and your old screen was at least functional (assuming you still have it), I'd try plugging it back in and seeing if it behaves at least as well as it used to. If so, that would indicate that the new digitizer has issues and you should probably pursue a warranty replacement. If you bought it here on iFixit, it will come with a lifetime warranty.

Give those ideas a try then come on back and let us know what you found! Your results, for good or bad, might help the next person with the same problem.