U do NOT need the original remote control device to solve this problem!
What happens is that in the event you leave the tv unplugged for any considerable length of time,is that the capacitor that stores the memory runs out of juice.
This is factory default setting.
All you have to do to eliminate this issue is to simply depress the channel up and down AND the power buttoms simultaneously and it will stop the channels from remaining on the screen,
the only problem is hitting all three at the same time,which as long as you have two hands you should be able to master.
Good luck,and glad to have been of help.
I have the same exact set,and although it is old,it works better than some new ones I have seen.
Doughface1, April 2009