This is how you upgrade the firmware on 337h. Now I don't know if there are different versions out there, but this works for the B11 version. Goto Menu, Setup->Firmware version you most likely have 337_B11 V0130_L. After upgrading you will have 337_B11 V0133_L which has the discrete video input codes.
I'm attaching the files necessary to this post. Download the zip. The firmware files are available from Olevia's site directly, but they don't have the USB drivers for it. After suffering with tech-support I finally found it through some luck on their site. They're included in the zip.
Power off the TV with the power switch in the back. And while holding CH+ and V+ on the front panel, turn the power switch back on. The blue LED in the front will blink once, release the CH+ and V+ buttons. The TV won't show a picture and is now in flash mode.
Attach USB cable to your PC and windows will ask for drivers. Choose, I'll specify location of drivers. And point at the unzip directory.
After successful USB connection, execute the FlashUpgrader.exe It will have automatically chosen appcode.inf as the Flash file, if not, choose that file. And after choosing, you'll see Flasher.HEX and AppCode.hex in the Files to Download section. Choose USB connection on the right hand side.
Now it got tricky, no matter how many times I tried I couldn't just hit Flash. All it would do is Copy the Flasher.HEX and then say waiting for target to reset and app would just hang. If I closed the app and tried again, this time it wouldn't even get that far and had to reboot my winxp box and powercycle the tv into the same flash mode again. So Do this instead
Then double click on the Appcoder.hex so that icon next to it becomes a "no" sign (red circle with a slash through it). It will say This file will not be downloaded. Then hit flash. This should take only a few seconds and your computer should beep as if a new device got connected. You also need to specify the driver for that as well. But don't close the app during this process.
Now switch the order, and disable the Flasher.HEX, and enable the Appcode.hex and also uncheck Reset Target After Download.
This will take a minute or two, but you should see the progress bar.
After it's done, turn off the TV. Remove the USB cable. and power back up. I remember having to power cycle it twice, but I'm not sure right now. Anyway, tv came back up, turn it on with the power button in the front, and goto the menu's again to verify that you have firmware 337_B11 V0133_L
For Harmony 880 owners, update all firmware and software for your remote. First modify the Watch TV activity and add additional buttons. Put the InputComponent1 and other discrete input keys on your menu and try it out. If it works for you, then you can Change the settings for the TV device and do Adjust Inputs and choose Method 2 for discrete input buttons and set it up accordingly.
Hope this helps.
After writing this, I see that I can't post zip files over 500K,
So here's the location of the files from Olevia.
Firmware: There are LOTS of these on their site for different months in 2007 but I've checked and they're all identical.http://18.104.22.168/support/Syntax...0V0133_L-C.zip
And the elusive USB drivershttp://22.214.171.124/support/Syntax.../USB_Drive.zip