How can I fix my Hotpoint WDF740 Washer Dryer at home?

I have a Hotpoint Aquarius WDF740 Washer Dryer. The wash cycles work fine, but when I try to use a drying cycle, it works for about 10 - 20 mins, then stops, all the lights on the display panel flash & it displays error code F-13. I have already taken the top off the machine & checked to see if the fan is running but can't locate it :s
I'm no expert, but is there anyway I can fix this problem myself at home without having to call out a repair-man?