Originally Posted by Runner1
Actually, fan pushes the air out thru a heat sink tunnel, this helps to cool down those "over heated" electronic components only when temperature is high. The fan does not blow air to other components if there are not inside this tunnel; definitely it needs another fan and there is a space for it.
I think I know one reason why some RX-D702B have heat issue problems and others don't. After removing the cover I noticed that there is a see-thru thin plastic shield glue internally to the cover, this shield covers the ventilation holes from the right side, next to the power button. I don't know exactly why JVC tekies decided to do this other than to protect anyone sticking a wire thru the holes and getting electrocuted by the capacitors (there are some next to this ventilation).
I went to the Local electronic store, the display D702B models (I believe older 702Bs) don't have this shield. So I decided to remove this plastic shield since is just internally glued to the cover; the temperature went about 6 degrees cooler, that's an improvement.
P.S. Anyone thinking of playing with internal components, capacitors hold lots of volts, even if recently unplug; They CAN BE FATAL!, use insulated gloves if not an expert.
I took runner1's advice and removed my plastic shield. I just received an older, but fully-functional unit. For those who still have this unit, perhaps someone might voice a theory for the plastic shield. Did any capacitors blow up in the past, warranting this protection? Of course... it seems paradoxical to avoid an overheating blast by... adding an element that increases heat. Was this an element added to increase the chance of equipment failure... and a subsequent need for repair? Was this an element to prevent dust bust up, and shorting/overheating?
I've now removed my own shield, and plan to service my unit every 3-6 months with compressed air, but if anyone has any plausible theories I'd love to hear them. Just using the unit this afternoon, I don't necessarily notice that much heat coming directly from the capacitor area, so I view the front-left vents as an extra venting options for the other heat-generating elements.