Did i damage my power supply?

last week, i cleaned out and tried to clean and get rid of the dust in my computer. I unplugged all the components (graphics board, dvd drive, cpu etc.) except the psu. Before i took out the graphics card, i covered the big psu fan on top of it with a cd cover, to prevent the screws from the bracket that held the graphics card in place from accidentely getting in. However, after i was done cleaning everything, i forgot to take off the cd cover ontop of the psu. i used my computer for a full week with intense gaming and i didn't know until the end of the week that i left it still on. I am wondering if the cover would of blocked the ventilation too much and cause overheating and damage my psu.

the psu also has vents on the side and back, but the biggest vent and only fan is on the top of the psu. Things have been working fine, but did i shorten the life or damage my psu in someway?

psu is a silverstone op750 that i got last christmas.

please help.
Thanks