Hd72 had colorwheel replaced turned on and worked for about 20 minutes made a sizzling elecrical noise and went blank. Turned off disconnected and reconnected power and turned back on and no picture. Tried again made same noise and showed just blank white picture. any suggestions

Colorwheel eeds replacement most likley it could also be a fan but I would assume its the colorwheel especially if it was real highpitched sort of squealing sound. You can get the colorwheel and free tech assistance from the guys over at www.tvrepairworld.com

the defrost cycle happens 1-2 times in 24 hours usually, and lasts 20-30 minutes.at which time the cooling process starts again.you may or may not hear the sizzle during the 20-30 minutes.if the frezer-freezes and the fresh food section is cold enough its probably o.k.

Do you mean sizzling from a certain area, like where the on off switch or mains input socket is, if so may be nothing more than a solder connection, If you know someone good with soldering , but be warned disconnect from mains and be careful, had a sizzling problem recently , turned out to be bed connection on mains socket.
pete

The power supply board is dead.Those high voltage transformers on the power supply board,one those power coil have a short in it,that why it cause this shutdown a have a loud electrical current noises.Tries websites like Shopjimmy.com.Ebay.com to buy a new refurbish power supply board for the replacement,should solved this loud electrical noises shutdown to tv.

3 problems: 1- the light tunnel is collaping and needs replacing. 2- the tunnel might be hitting the colorwheel, which is now making that wierd noise. and 3- it needs cleaning. these models are famous for these 3 problems. there are no filters, so the dust just gets sucked in. the glue on the tunnel wears out from heat after a while. the colorwheel motor also wears out from heat and dust. the parts are not that expensive and they are relatively easy to install. contact an infocus authorized service center (from their website) and either get these parts or send it in.

tunnel- 306-0095-01
colorwheel- 525-0146-00

WHAT THAT MEANS IS UR TUBE IS DONE U CAN HAVE IT FIXEDWITH A REPAIR GUY BUT IT WII B ONLY A MATTER OF TIME TILL IT GOES OUT AGAIN BUY A NEW TUBE 4 IT OR JUST GET A NEW 1

Hi...there,
It's seems you've got a busted backlight inverter. Sure you can...you've got a 3yrs warranty for parts.
Send it back for repaired...

Mine did the same thing. The bulb is used up...replace the bulb. That fixed mine, working great again.

Good Day;

The TV's front panel may be bad, manual buttons. TEMPT FIX; remove speaker, cloth covered, cover, disconnect cables. TV will work but only with remote.

Good Luck!

Pix looks like a light pipe issue, inside the Light Engine. as far as the shutting down, could be a bad fan causing the grinding and when stopps the DMD turns the set off.