Help --- Master EverDrive upgrade OS Failed!!!!

[fredb]

Hello

I have a Master EverDrive (manufactured by Krikzz 05.07.2011 v1.2).
I tried to update my Master Everdrive.
I was on os-v4 version and tried to upgrade to os-v9.

I inserted the SD card into EverDrive and put the EverDrive on the Master System II. I turned the console and appears the main menu, at the bottom of the screen showed that the OS v4 installed. Then I decide the upgrade OS.

In the main menu i selected the option OS Update and selected the file os-v9.mso. The EverDrive began to update the first step showed that was updating . . ., in the second step showed that he was verifying . . . and stayed for more than 15 minutes.
How not to get out of this step and did not respond to any commands I turned off the console. After this , when I turn on the console show the sega logo and stands still at the SEGA logo.

Is there any way to recover the OS EverDrive via the SD card.
Can anyone help me? Thanks.

[nuu]

Just backup all the roms on the SD card and reformat it. Then try again with OS v9.

[fredb]

I tried this, and did not work.

[nuu]

Maybe you need to wait more than 15 minutes?

Otherwise, if it still doesn't work contact Krikzz.

[phoenixdownita]

The V1 Master EverDrive has a rescue OS installed so you can try to unbrick yourself:
https://krikzz.com/forum/index.php?topic=1072.msg10438#msg10438

basically start the Master System with the MasterED pressing Up+1+2 (have a SD card ready with the other OSs http://krikzz.com/pub/support/master-everdrive/v1/os-bin/ )

Depending on how old the rescue OS is you may need a small SD card formatted as FAT16 ( FAT32-only support was added in v7 check http://krikzz.com/pub/support/master-everdrive/v1/os-bin/chagelist.txt ).

So I remember that going from FAT16 to FAT32-only version was ... tricky .. can't remember if upon successful flash you get a "bad SD" error or alike, at any rate you need to reformat the SD card (or use a different one) after that.

Krikzz never said if it was possible to flash  the rescue OS itself with a FAT32 only version (like V7 or above) ... pity because it makes it a little more complex to pass that hump in case of bricking.

You said you were on v4 so chances are your rescue OS is v4 or older ... so you may have to go thru an intermediary hop first ... try to go to v5 then v7 ... from there on out you need a FAT32 SD card .... and then v9!

If you brick it again once you are in V7 or higher you need to go back to a FAT16 formatted card (small card, up to 1GB usually work best for this) given the rescue OS stays whatever you have now.