This subject is an endless issue for me, because our family uses a media player (eg WDTV) and HDD so the HDMI input is important for us when visiting hotels. Each hotel/TV seems to be different. Most hotels have "TV services" that comes up automatically when TV is turned on. You can buy pay channels/shows and various other things. I can workaround those by hitting the "Input" button on the remote or TV (but often this must be done from the "initial" (channel 0?) channel that comes up at TV turn on (the TV services channel). I just left the downtown Embassy Suites in Denver (LG TVs) where they have eliminated "all" TV services (no pay stuff) and force you to watch their channel lineup (likely some cable provider). But I couldn't switch to the HDMI input at all, because there is no channel zero (because there is no TV services menu). It just defaults to what they call Channel 01. When the "Input" button is pushed the TV says "This function is not available now". I tried to reset the TV and also disconnected the cable from the TV. This somehow worked, although I do not believe the "reset" did the trick -- I think it may have been the cable disconnection that somehow brought the "Input" capability to life.
There seems to be a bunch of ways to workaround the "Inputs" problem. I used the 5-or-more digit codes suggested in this forum, the multiple selection of the 0 key at TV power on, the MENU method of trying to "turn off" settings (in my case all settings were already off and unlocked). All these failed for me. I needed to be on channel 0 for "Input" selection to work, although these Embassy Suites LG TVs in Denver almost defeated me.
It does seem that the hotel TVs indeed are different from home sets, but the myriad of workarounds tells me that, even though I have always managed to find "some" way to switch to HDMI, I continue to be suspicious that soon I will have tried all suggested methods and still not get the "Input" to work.
I like the idea of taking to the engineering guy, but continue to think that, with my luck, he may be of no help either. Plus hotels often put a sheath over the cable connector that usually prevents you from disconnecting their cable (in most hotels, thankfully, this is not needed if you stay on Channel 0). I will continue to try the suggested methods that this forum have provided me, and am grateful that at least one of the methods always seems to have worked for me.
I am grateful for all posters who have posted on this subject, and hope that you continue to offer your newest experiences, as this problem seems to come in a lot of different "flavors" given the latest antics of hotels and their exasperating TVs.
What an endless hassle.