broken digital thermometer

My digital thermometer reading was noticed to stay at around 156 after I removed from steeping grain water. I could wiggle the wire and could fluctuate by 30 degrees the temp readout. I believe it steeped at the right temp range but cannot assure it did. The cream ale is darker than expected. Fermentation lag time was around 20 hrs at 72 degrees with 1/8" krausen formed after 30 hrs. What should I look for to know if it is ruined?

By the sounds of your description, you are using one of those oven thermometers than has the temp probe connected with a oven-proof wire. As you have found out, they are not waterproof. Putting in in the oven to dry it out might work, or it might be toast.

I am more concerned to know if the beer is ruined. Not really worried about the thermometer.