Menu flashes on while TV is on

Now I dont want to step on any other repair shops toes as it were. so im going to give you some advice. I think your dead on about the switch. i have seen this condition here at my shop a few times and what i have done to fix it is replace the switch pcb cuircit board... this has fixed it 90 percent of the time. BUt....i have seen other problems that cause this.... there are 4 possibility in this case. 1 switch pcb. 2 bad infared sensor 3 bad cables. and unfortunatly the last one that bad main board. the other shop mentioned. Some condition is occuring that is telling that main board (processor) that "hey someone is wanting to see the menu"so put it on screen. for me that comes from the front panel and the remote sensor and the remote. since you have experience with some sets try this. ......remove the front panel real easy. remove the 4 torx screws in the back and remove panel its that middle one. disconnect cable from buttons turn it on with remote if the menu doesmt pop up then theres your problem. about the part and where to get it i believe union electronics sells rca parts.. you have to get the model number off the back and be sure to include the ext it will be hd52w59yx1 or something like that. well good luck and let me know if i can offer any more advice