I am not getting sound

hit MENU button and scroll around till you see autoprogram TV...use arrow keys on remote to scroll MENU!!!

http://www.comcast.com/MediaLibrary/1/2/CM/VanityURL/documents/us_electronics_uf4200c_manual.pdf here is the link to the 200B remote manual and the codes are on page 3

0180, 0171, 0000 if your remote has a GREY ok/select button on it,
20675, 20821, 20000, 20593, 21593 if your remote has a RED ok/select button on it

Need actual Mfg. so I can have Comcast program the Remote??? Comcast has NO listing for the program numbers for Vivitek.

code TV/ 0156 or TV/ 1256 (or TV/ 10156 or TV/ 11256

After fooling around with all of the buttons, and disconnecting the power to the TV, it occured to me that it may be the Comcast digital cable box. I unplugged the cable box for a few minutes, plugged it back in and the TV works just fine!

I plugged this code in and it worked:

10000

Good Luck

Try
10813
11365
10032
10039
10019

try repairhelper.com

Its possible that you changed the channel or the input line your TV gets the cable signal from. unless you caused more of a problem while trying to fix it, I would suggest you to go through the TV(not cable) channels to see if you can find the one that gives cable picture, or to go through the different input settings(TV/AV on older TV's, and 1, 2, 3 etc on newer ones). one general icon for the later is an arrow going into a circle. I think its the "select" button on your TV remote. Good luck