Mower deck Belt keeps throwing on White brand mower HELP!

I have a White brand mower and the belts keep throwing. Both the one that turns the blades and the one from the rear to the deck I can't figure out why. Anyone else have this issue and what helped it? My husband went into the hospital and I had a friend work on it for me. I *thought* it was fixed but no such luck. And I don't know if a guard for the belts is missing either (making it throw). I'm at a loss and am going to get rid of it if I can't fix it. Any help?!
Thanks!
Michelle

OH, it's a zero turn, sit on (riding) mower. Not sure of the model or year, don't even know where to look

Model and serial number tag is normally under the seat on all MTD/white products. If you can find that information it would help us to narrow down what possibly causes could be.

ILENGINE said:

Model and serial number tag is normally under the seat on all MTD/white products. If you can find that information it would help us to narrow down what possibly causes could be.

Click to expand...

SERIAL #: 1C188G90011

MODEL: 53AC225G190

The photo I attached (hoping it works) looks exactly like my mower. It's a weird bug shaped one