SamyGO

take any smd-part datasheet you like that contains a temperature diagram for hot-air soldering/reflowing as a guideline and use half of the temperatures.
the biggest risk is called popcorning when some ram-chips that are slightly hygroscopic are heatet too fast over 90(100)?C and the micro amounts of water they contain wants to get out
in almost every how-to you'll find there is another temperature stated, depends on the weakest component on your PCB... but your goal is to at least soften the solder under your problematic chip...
it would be a really interesting discussion what oven to use as burning gas produces considerable amounts of water while electrical heated ovens don't

Hi There, I had exactly the same issue, I baked the mainboard in the gas oven at 392°F for 10 minutes and problem has been solved. I didn't removed any component and only one label ahs been melted but without inconvenient for the board. Thanks for the tip!