The high voltages in tv's attract dust particles,and a fine layer eventually covers the internal surfaces.Depending upon where the set has been used decides what the dust smells of,and of course as components warm up,the scent is given off.
I've been amazed (and intrigued!)by some of the pong's emmitted by sets I've encountered over the years.The worst of course were from Pub's and smoker's abodes,where the inside of the set is covered with an awful brown sticky goo.There,that's put you off your dinner?
The solution is to hoover out the interior carefully using a small brush to dislodge the main dust.Then,use an electrical equipment cleaning solvent to wash the printed circuit boards etc.Don't use "foaming" type cleaners,you need special stuff that dries quickly and does'nt leave any conductive residue.I've used something called Ambertron,but Maplin may have this or similar.CPC can supply this and several similar products.
Needless to say (hopefully)Don't do this with set connected to power!!!!
Hope this makes your "smellivision"(sorry!) more nice to be near.
Regards,
Nick