Problem with HDMI adapter and viewing on TV

[calail]

This past week I decided to upgrade my Galaxy Tab 2 to a Galaxy Tab 4 running KitKat 4.4.2. I love the idea that it has an 11-pin port for charging - so tired of that 30-pin plug And, it's faster, and sweeter all around. Unfortunately, I can't display my tablet's screen on my television. I have no trouble with this configuration on my Samsung Galaxy phones (S4 & S5).

My connection looks like this:
HDMI cable connected to TV. TV set to HDMI port.
HDMI cable connected to HDMI to MHL adapter (purchased here: New MHL Micro USB to HDMI HDTV Adapter 1080p for Samsung Galaxy S3 S4 S5 Note 2 | eBay)
Power adapter connected to HDMI/MHL adapter.
Lastly, HDMI/MHL adapter connected to tablet.

After reading several forum posts (here and elsewhere), I've learned that the Samsung Galaxys often need a 5-pin micro USB to 11-pin micro USB adapter, so I purchased one from Tiger Direct yesterday, and adding to the connection hasn't seemed to make any difference.

I get nothing on the screen. When I connect this same configuration to my Galaxy S4 or S5 (I've tried with both), I get a popup on the phone(s) saying "HDMI connected" but when I connect the tablet I don't get this message, and of course, no display to TV.

I've also tried activating the "screen mirroring" feature on the tablet, and that doesn't seem to make any difference either.

Any ideas what's wrong? How can I make this work? TIA