Not every fixer is a diamond in the rough! Some places just can't give you the benefits you need to make money. Some owners will think think the value is much higher than you do, or they owe too much on the property to sell at a reasonable price. Some places just aren't layed out right, are structurally unsound, or are in an area that won't attract decent tenants. Some places just don't justify the fix-up costs for the return.
The ideal property needs no major layout change, is functioning presently as a rental, and just needs updating, a good cleaning, and possibly new tenants. These are things easily fixed, that almost anyone can do themselves without a contractor or permits.
We also look for basements, separated utilities, parking, and good fire separation between units. Bonuses are big ticket items that are already done, such as roofs, HVAC, electrical, etc., that can kill the budget!
We are not beyond major reno's if the return is worth it, but remember, you are a real estate investor not a contractor!