[Windows Phone 7 Development and Hacking] Martin7Pro:
I have very long last night. I have resent requests to all people refered me about this method success and do any more searching.

When I have begin work on halbrick solution in summer, everybody told me unbrick is impossible. After 3 months the same people was wery happy with unbricked phone. I had one big condition - to publish only informations, which I have tried on my phone and which I have confirmed from more then one man.

SPL 5.xx downgrading by ROMUpdateUtility success confirmation I have got to mailbox from one people a month ago. I did not believe it and write this unbelieving everywhere. He has HD2. But, after receiving the same from other people and also one with HTC7Pro I have tried it. For my phone nothing was happened - stay halfbricked. But, when I have got success confirmation from one man with HD7, I have believed it. After big thinking yesterday evening I must wrote this is impossible. I have recontact this HD7 man and he is not sure, if really used all steps. I mean he was not remove RUU_Signed.nbh from directory. May be he has removed SPL_Signed instead, but he do not remember it today. Please, do not try something similar anybody.

For rdia

: This is really my total mistake to translate here one not fully confirmed tutorial. Big sorry. But, my biggest sorry cannot help your phone (if you have it fullbricked, I do not know it. Confirm your state, please!), I must do more. I will work on solution, but, I am very afraid, that is long way with uncertain result. If too long time occured, send me PM and I try raise XTC solution for you. I have writed on my tutorial "it is danger, may not work, use on your own risc", but I have write here post to you to try this point. Send, please, again, what is your phone state now. M.

MORE:

I have got any reconfirmations now. Much people has fully unbricked phone by OEM update forcing, some after GoldCard SPL downgrading, any after mentioned danger ROMUpdateUtility using.

But one Slovak man has fullbricked phone after long time from SPL downgrading by GC(!!!), may be any causality:

He have buyed halfbricked HD7 in bazar.

He have forced OEM update to "small" halfbrick.

He has used full GoldCard to downgrade SPL (only SPL, not Radio probably).

He had nice fully unbricked phone with SPL 1.17 after it.

After any days, he has apllicated HSPL to this phone. All liked normally.

After HSPL, he tried any custom (probably XBMod) ROM flashing. When 10%, Flash Error 260 occured. After it device is totally dead!

What do you mean about it everybody ? May SPL downgrading in combination with newest Radio (probably), with HSPL and with custom ROM flashing cause this Fullbrick?

He does not know, how full was him battery in time of flashing.

Edit(17th December 2011): I have tried flashing DFT ROM OS Version 7740 (http://xdaforums.com/showthread.php?t=1350437) with full success on my phone.

Then way Halbrick --> force OEM Update --> "small" HalfBrick --> downgrading SPL by GoldCard (may be simplified without CID reading) --> Unbricked state --> apply RSPL/HSPL --> flash ROM is probably care independent of actual Radio version. But use carefully and on your own risc.