jvc th-m505 subwoofer powers off?

i have a jvc HTIB it was given to me by my friend he had the sub in a very tight enclosure very little air flow and as soon as i power it on the sub powers on then i hear a click and it shuts off now on this model(TH-M505)the suround speakers are run off of this sub i have been told it may be a temp scensor and i could bypass it and solder a fan directly to the board i wanted to know if any on could tell me where on the board i can solder the fan too i would love to get this unit working again for my own use