Originally Posted by asere
Is it necessary to install cooling fans on the F8500? I notice it gets hot but I don't know if that shortens the tv life or not.
Necessary? That depends on your personal definition of the term, as well as the conditions the set is subjected to (ambient temperatures, available airflow, continuous runtimes etc.). Simple fact is, electronic components tend to last longer if they don't get too hot, so keeping things cooler so they never get more than warm (the individual components, not merely the exterior of the equipment) potentially increases their MTBF.
How long the resultant potential lifespan increases due to added cooling will depend on how well the original equipment was designed to keep its components within optimal temperature ranges vs how much cooling the add-on setup provides. Personally, for a set that cost me almost $3k, 2-3% of that cost in added ventilation seems like cheap insurance to me.
I also have an Onkyo 5008. Had a small vent fan on it from the 2nd week after buying it. Had a heat related component failure ~18 months in (see the threads for HDMI board failure in the Onkyo xx07, xx08 and xx09 series). Got it fixed and put bigger, higher CFM fans on it and luckily, haven't had any further problems over the past 2+ years. Other folks haven't been so lucky, with their units being sent in for repair numerous times for the same failure reoccurring several months after the last repair.
Are the larger vent fans on the 5008 the reason mine has been problem free since the repair? I can't say for sure, but what I CAN say for sure is that the unit has a hidden menu that pulls up an internal temperature sensor. The vent fans I have on the unit now keep the internal temp sensor about 20 celsius lower than with the smaller fan I had before and up to 30c cooler than without any fans at all (the internal temp sensor reads in celsius only). At $30-$35 for the fans + controller, it was cheap insurance for another $2k+ piece of equipment.