ak57 said:
man, why do many hitachis have this problem? i can hear it when the volume is at 40 plus
If I am not mistaken there are two common faults that occur with mid-range HD ready plasma's, and not just Hitachi's.
1. Fan cooling the display CPU.
2. Transformer hum.
Both have generally been corrected by newer releases of some plasma models, which is why some people complain about noise and others don't, for the same plasma model.
Unfortunately some display's using the Faroudja scaling chip up to 1024x768 or greater for HD, require a cooling fan. Where-as a model below may not have a fan, because the amount of processing and therefore heat generated by the CPU is far less. For example the LG 42PX4DV doesn't have a fan, where as the 5DV model does. The difference is purely in the scaling requiring the addition of a fan in the 5DV model.
Some people on this forum have complained about the 5DV fan noise, and yet, I don't hear mine at all (well not unless I stick my ear to the back right-hand side of the screen. Then again, my screen was manufactured in December 05, so they may have cured the issue by then.
If you aren't worried about taking the back off your prized screen, then sound proofing could always be added (taking care not to cover the ventilation holes).
TGL