it's just a lockup at this point. there have been several lockups like this before and they were just that.. a freeze. nothing came from it cause it didn't allow any code to run.

no, because the security sector is signed, any change would make it invalid.

it should copy it over, but the SS of another HD will not work since the model and serial don't match.

no, because the serial number will not match.

if you don't have YOUR security sector for YOUR drive, then you are out of luck. the security sector contains among other things the serial number of the drive. if you didn't make a backup of that, or the entire drive, then the drive will never work in any xbox anymore, unless someone bothers to write a modified firmware and an updated hdhacker to support it.

sounds to me like your HDD is missing the unique security sector.. without that, the drive will not be recognized.
did you make a sector-by-sector image of the drive (full 20 GB), or only the data on it?

Check xbins. No links are allowed here as that is copyrighted material.

I didn't have that white sticker, just the big one.
@sasoseso: thanks, I thought they had done that only on the dvd-rom, not in the KV too.

what extra white sticker?
as for that strip, I could'Ve sworn it wasn't visible till I started heating.

I sent in a 360 with a fried southbridge, so it was definitely a dead board.. got it back a week later:

First of all, the new seals they use (green, wide kind) are heat-sensitive.. if you heat it up with a hairdryer to remove it, a plastic strip reading "Microsoft" sort of melts through to become visible.

Second, the stickers on the MB had a different serial number than what I sent in -> they gave me a repaired MB, not a new one.

Third, apparently they copied over my entire NAND contents.. all settings but TV setup were intact, although serial number matches the case it was sent in with (case wasn't replaced and didn't have the same serial as the MB), kernel version is still the slightly outdated 5766 kernel. The DVD key changed completely, though (they put in a benq), which means it either is dependant on the serial number or the board can be set into some mode or maybe a software to replace the key. I think a possibility is that the drives are actually preflashed with the randomly generated key, and the 360 only adjusts the keyvault to match it once run with the software or put into that mode. Has anyone tried setting the keyvault dvd key to all 0 before? or all FF?

just make VERY sure that you heat it up slowly and don't blast it at full heat, and not too long.. keep moving it, or the MB will start "bubbling" and be ruined.. the GPU will never attach itself then.

it may be on purpose that some legs are bridged.
it's more likely that you damaged something while soldering the chip in, i.e. caused a bridge on the FW chip, damaged a trace or disconnected a pin on accident.
if possible, take a sharp (!) closeup pic of your soldering spots.

heatgunning wouldn't really be a good idea, there's way too much plastic around.. I can probably do that when I get access to a proper smd rework station with a selection of fine nozzles.

no, none of that will help much.

the potentiometer is working fine, I measured it multiple times.

the usual spot, of course.. the GPU. that's 99% the reason for a RLOD, and fits in with your artifact issue.

if he had killed the flash, it wouldn't run in mode B.

classic ROD, most likely it was already damaged and the bouncing about was the final straw that broke it. if the heatsink had slipped (which it can't), you'd just get overheating (highspeed fan + 2 red lights).

no, there's no other way.

one at the top, one at the bottom.