I finally managed to execute below commands successfully after typing "su" command in terminal app.
su [press enter]
chmod 755 /data/flash_image [press enter]
chmod 755 /data/mtd0.img [press enter]
Then I have done your Step 6, my Desire device showed "hTC" image while connected with the PC, HTC Sync was on, goldcard was in Desire (have tried not using goldcard also). But I don't understand what you meant by
"If it returns with a device, then you're good"
Then I run the RUU at hboot 0.75 (my Desire is currently 0.80), it said ERROR 140 Bootloader version error. What went wrong? Pls help!
The commands you typed in the terminal are incorrect.
[press enter]chmod 755 /data/flash_image
[press enter]/data/flash_image misc /data/mtd0.img
There is actually an easier way to downgrade your bootblock.
Since your Desire is already rooted, you just need to use a custom recovery to apply the update.zip from the thread below.http://android.modac...d-b0rked-fixed/
You do not need to follow the other instructions in that thread, you just need to apply the update.zip linked there.
That particular update.zip was created to fix the USB brick issue, but it also allows you to run an earlier RUU and downgrade your bootblock.
In short; copy update.zip to sdcard - boot into custom recovery - apply the update.zip - reboot phone - connect to PC - run RUU file
Edited by Raz2133, 08 August 2010 - 04:38 AM.