I have a semi-shaded area right off my back patio. This area stays shaded until 2pm. After 2pm there is plenty of sunlight on this area for the remaining summer hours. My first attempt to create a better looking lawn was to lay 2 layers of TifGrand Bermuda sod extending off my patio. Some parts have taken and some haven't. The pic below, I pulled up the dead TifGrand but you can see beyond it where there is a large dead spot.

I just need to know if I'm dealing with a fungus or do I need to pull up the bad sod and lay new?

Deep and infrequent is the mantra. What does that mean? Infrequent means no more often than once a week in the hottest heat of summer. There is the rare exception in Phoenix or Las Vegas where you can water every 5 days. In the cooler months it means once a month. Deep means you put enough water in the ground so the grass will last until the next time you water. Most people start out watering one inch per week and adjust from there. With my soil, grass type, shade situation, heat, humidity, wind, and mowing height, the lawn only needs 3/8 inch of water per week unless we're really having a prolonged drought. Then it goes up to 7/8 inch per week. Everyone's situation is different. You'll have to measure the output of your sprinklers to see how long it takes to get a full inch. Use a tuna or cat food can to measure.

Why do it this way? Primarily because weed seeds need continual moisture for germination. Secondarily the deep cycling of irrigation will force the plant to grow deeper, more drought resistant roots.

I would back off on the watering and watch the spot to see if it shrinks or grows. If it spreads even with less frequent water, you might need to treat for disease.

For now, it still looks bad. I'm thinking there is too much shade but still, healthy bermuda sod should last a deceptively long time even in some shade. That looks like a disease from too much water.

I'm ready to punt to TW.

Not only does this area battle shade but it also get's drenched as it's right below the drains from the roof.