What to do? Black screen after applying new theme.

Hey, first of all, my menu system was 4.2 (USA), i have wiikey 2, and also some soft modding to use usb loaders. Have homebrew, and for some reason, bootmii was removed as primary boot just a few days before this mess. The problem was today, i tried to install a new wii theme, and the installing process was perfect, then the app quit itself and i was sent to homebrew, then i restarted the wii to see the theme. And i get nothing more than a black screen! I have been searching info, and I saw the savemiifrii, and it works perfectly in my wii. But i dont know what to do after the 4.2 (USA) sign appears in the black screen. I saw in some places that putting a disc with newer system could help, the only one I know is Metroid Other M right? But Im not sure if it will work with Wiikey 2. And its dual layer disk :S what can i do? Please help me! Is there any other game with 4.3, or another way to fix the F!"#%!" system....:(

Moved to brick section

Do you have bootmii as boot2 or priiloader installed

boot2=drive light flashes twice quickly when you power on
priiloader=hold reset while powering on

Well, it doesnt flash twice when i turn on the wii. But I remember that when I started softmodding the wii, it was almost a requisite to install bootmi, i remember that when i turned on my wii in past months, and bootmi was the first thing that appeared, but it was some time from that. But I remember that when i used homebrew, an d used the home button, it appeared bootmii in the menu. And also I think I used some apps that automatically ran from there when i choose that option. Now that I think, do I need to have the sd card inserted with the bootmii information to load the bootmii at first like before?

If you can find a bootmii folder on your SD card, try putting it in your Wii and boot. If bootmii loads see if you can load HBC. If so go to MyMeunify and load a known working theme.

yes if you still have put the bootmi folder on the root of the sd and power on the wii and it should boot into bootmii

SD:/Bootmii/armboot,ppcboot.elf,bootmii.ini)

Do you have priiloader did you check

If you have Bootmii boot2 you can try what Krafter said or you can restore your nand from Bootmii if you have a working backup. If all that fails, you can use cboot to run dop-mii or MMM to recover. Either way there's no reason you shouldn't be able to recover from this brick.

Lesson learned the hard way to not install custom themes. Look at how many warnings there are on this and here's another one to add to it.

If you don't have bootmii or priiloader, or a patched ios70 with corp or a modchip, update your wii to 4.3 via Metroid Other M- no modchip required. Just insert the game at the recovery menu and it should update to 4.3, removing the theme in the process.

well, i erased the bootmi folder long time ago, cause its the sd i use for my camera, and about priiloader, nop, i dont have it. And about cboot? Im not sure how to use that or what is it, but i dont think i have it installed. I think i can get the metroid other m, but how do i upgrade the system to 4.3? I mean, when i use savemiifrii, it appears the 4.2(USA) sign, but what next? Do i instert the MMM game? Or it has to be inserted before? Im really scared about loosing the wii....Its my brother console...he will be very mad :S

If you need a bootmii folder
go to mediafire.com/mauifrog
apps ->bootmii -> ntsc bootmii folder
is

I searched the tutorial i used to install homebrew and bootmii and all that, and i found i only installd bootme as IOS, and not as boot2 so it cant help i think. In some hours a friend will lend me the metroid other m disk. But I dont know how to use it. When I use the savemiifrii and appears the 4.2(USA) thing in the bottom what do i do next? Cause it appears like if nothing happens when i enter a disk. Or thats what i think, maybe its cause the games have a older system menu right? and it doesnt make any change.