Why isn't my Nikon D3200 display not changing in manual?

My camera recently had a circuit problem (and wouldn't turn on) and today I just got it back from being repaired. It works as good as new - except one thing: on live view, on manual, the screen doesn't preview exactly what the photo should turn out as. It automatically adjusts the preview as if it were on automatic, instead of showing what my settings are. It worked fine before it had the problem I mentioned.
Does anyone know what the matter is?

Talk to the people that repaired your camera. Or maybe some settings in your Menu got changed. Read your manual.

Agree with Al. Read the fine manual.

The person who repaired it may know.