Very early production games needed a new SD card (see below) before updating. You could try updating your game or check with Stern tech support first.

From a Stern service bulletin -

In order to assure a successful update to code version 1.51 on Whoa Nellie games, please be sure that your game is at code revision level v1.50 prior to attempting the update to v1.51. Version 1.50 was sent to all customers as an SD card in order to facilitate installation. If you did not receive the v1.50 update kit from your dealer or distributor please contact Stern Technical Support at 1-800-KICKERS and we will send you the appropriate SD card. As always, please follow update instructions.

What's Whoa Nellie even need code for? Cant the dings and dongs just be automated like regular EMs?

It's an SS though.

Mine would never update so Stern sent me a new SD card with 1.52 on it

New speech call outs, additional music track, rules options, etc. I know you're probably being sarcastic, but thought I would offer an answer anyways markmon!

Mine was 1.1 and I apparently updated to 1.52 successfully, but now I'm a little concerned about the implications of doing the update without having been on 1.50 and/or without the replacement SD card. . .

Sometime and always during game play, my Left side GI blink (flast/go out for a sec), I feels like normal game play eddect as it's just off and right back on - could it be a short in a switch somewhere? Does certainly does not seem correct -- anyone else see this left GI issue?