Actually I also not sure what happened on my Wii U, I just packed it back to box since I left Malaysia for one year. After I came back the hdmi port is not function anymore, may be too long not on the Wii U? 

You sure it's not the TV or HDMI cable? My HDMI cable bundled with the PS3 sometimes also black screen.

Yup, it is not the tv since my PS3 just working fine with the tv hdmi port, i also use the hdmi cable for wii u on PS3 as well.

WiiU T/Shooting
You got try this guide?

Just tried this, but still not working. 

I am  having lots of problems with external hard disks....just to share:
Section A: Wii software on external HDD (NTFS Formatted HDD)

1) WD Passport 1TB , single USB port, SATA 3.0 - Use this for storing Wii games....most of the time can run, but i have occasionally get crash or hang before.

2) Customized HDD external box + old 80GB HDD ,SATA 2.0 Y cable - Use for storing Wii games until i ran out of space and changed to the WD. It works perfectly fine.

3) Try connecting the WD Passport 1TB and the Customized HDD external box above using powered USB hub....doesn't work at all, Wiiflow does not regcognize.

Section B: Wii U external HDD (WII U formatted HDD)

4) Cliptec external HDD box + Intel 60GB SSD, SATA 3.0 single cable with Transcend Powered USB hub - Can detect but CANNOT FORMAT THE HDD (Conclusion: The controller used by the Cliptec box must be not compatible with Wii U).

5) Archon external HDD box + Intel 60GB SSD, SATA 3.0 single cable - can detect but lots of problem.

6) Archon external HDD box + Intel 60GB SSD, SATA 3.0 single cable + Transcend powered USB hub - able to detect, format and use. But occasionally, it will crash and asked to connect the Y cable...not really sure why. Doesn't seems to be really stable, but it's the best working model so far. Need to monitor for stability.

7) I got ambitious. I try to hook up WD Passport 1TB (Wii games HDD, in NTFS format) + the Archon SATA 3.0 with Transcend powered USB hub :  Major failed. It keep saying something one of the hdd is not being formatted correctly (which is normal if just connect alone) and keeps going back to main menu and restart and i can't do anything at all.

Conclusion:
1) Connecting both Wii HDD (NTFS) together with a Wii U formatted HDD is a MAJOR FAIL.

2) If you use those external HDD box with your HDD lying around, it will depends on whether it is recognizable by WII U. Not all will work.

3) If you use customized external HDD box even if it works, might not be stable.
Anyone has tried to use branded external HDD like WD, Seagate, Toshiba etc as Wii U external HDD??? Please share your experience. I haven't try a branded external HDD for Wii U games yet...because now minimal also like 500GB, total waste. I won' be even using 60GB. So perhaps a good high speed quality flashdrive is a better solution than HDD? (Haven't try yet...)

I have ordered a SATA 3-->USB 3.0 cable from Lazada(arriving end of the month) and will be using it to test the WD Passport stability with a Y cable.

Sorry to hear that. But try to get quotes on fixing WiiU. Or maybe Nintendo might release a WiiU Mini just like the Wii Mini.

Usually HDMI port is integrated with the MOBO. Should be the port problem (which PS3 also happens before). Saw/read before that it will cost a MOBO to fix the HDMI issue, so for the best I think better stick to Component Cable as WiiU internal memory also a integrated piece. If you change MOBO = you're casting away your DLC/Digital also

Guys,

I'm looking for pre-loved Wii U games. Know where can I get them? 

New Super Mario Bros. U + New Super Luigi U
Super Mario Galaxy 2
Mario Party 10
Captain Toad Treasure Tracker
NES Remix

Thanks.

any used wii u games ? kindly offer me , currently collecting wii u games

OMG I got some competition 

5 more mario titles , then i will complete all mario series for wii u ...

OK I lost 

PM me if you are willing to let go some of your collection