Did you do a factory reset before flashing the ROM? If not, there's no chance of it booting, as the Sense ROM settings will be incompatible with Oxygen.

If you backed up your apps and data before flashing the ROM (e.g. Titanium Backup), but didn't do the factory reset, then do that from recovery and see whether the phone boots then.

If you are sure you did a factory reset, then we'll have to think what else it might be (but in this case, try it again just in case).

Did you take a nandroid backup with Amon RA? If you did, you can restore from that and get back to your original ROM, apps and data. Then read the guides, make sure you have all the backups, and try again.

If you aren't sure of your backups and don't have a nandroid, then there's one way of getting your data back that I've talked people through before now, but I hope that isn't necessary!

Final thought: when you have Oxygen working, do not install ROM Manager again! Look at the top of this forum and you'll see a sticky thread telling everyone not to use that app. And never try to take a backup using ROM Manager - we've seen a lot of phones usb bricked by doing that (recoverable, but not something you'd want to have to do). Just boot into recovery and do everything using Amon RA.

 

You can back up contacts (and some other things) by selecting a backup or export to SD option from within the app, but I'm not sure I understand what you say you did. Specific backup apps, as described here, are recommended. There's no harm in having multiple backups.

Right now there are 2 options:

1) Trust your backups. Do a factory reset from Amon RA (I've never used Amon RA, so don't know the menus, but if you can't see "factory reset" look for "full wipe" - it will be something like that). This won't affect SD card contents, but will wipe all data (including user apps) from the phone's internal storage. After that I expect Oxygen will boot, but you'll have to restore your data from the backups you have (either on SD card or from google).

2) Don't trust your backups. This one is more fun! Flashing Oxygen has erased your original ROM. But as long as you've not done a factory reset, your user apps and all user data still exist (dalvik and cache don't matter). But how can you use them?

The answer is, if you can flash a compatible ROM without wiping, you can then install Titanium, and any other backup apps, and make your backups. Nandroid also. So what's a compatible ROM? If your previous ROM was Froyo (Android 2.2) I'd suggest one of these. Choose a ROM without a radio (i.e. one of the init.d versions). If you know your previous software verion, take the one matching or nearest. Otherwise try the 2.29.405.5 init.d ROM. If you've already flashed the official GB update, try this one, but so much is different if you did that then I assume not.

The idea is, if you've not done a wipe, your data are still there. They may stop a non-Sense ROM booting, but if you can replace it with a compatible ROM, it will boot. Then you can do your backups. The ROMs I've suggested above are the most compatible I know, and flashing them has worked before now. If you can boot the phone, take a Ti Backup, use SMS Backup+ or MyBackup Pro to back up calls and messages, then try again (only with a wipe this time - and a nandroid first!).

If for any reason that doesn't work, do the factory reset from recovery then boot or flash the rom, and restore whatever you can.

 

rom manager is death to desire at the moment
even worse for pvt4 40000 devices as it uses cm 2.5.0.7 fake flash with does not support the 40000 erase size nand chips. this means its guaranteed to break the device every time.

always manually boot to recovery using voldown+power and download the roms from the xda website put them on the card and flash them.

most of the roms on rom manager website are hugely out of date

 

If you are trying the second option, then just put the ROM on the SD card (doesn't matter whether it's a goldcard or not for a ROM flash), install from recovery. Wiping cache will do no harm, but the whole point of that one was to try to get the phone booted without wiping the user data, so avoid the factory reset/full wipe option, which would normally be the prerequisite.

It may not work, in which case it's probably a matter of doing the factory reset and flashing whatever ROM you fancy. But it has worked for a couple of people in the past when they've tried a first ROM install, forgot to wipe but also forgot to take a backup so didn't want to wipe either.

 

nope thats a bootloop

youll have to wipe and start again, its goosed

 

Well I'm sorry the trick to keep the data didn't work - it's a bit of a punt, but it's come off a couple of times.

Anyway, you've now had a bit of experience with this, and seen that problems are fixable, which is an important lesson. Just remember, take a backup from Amon RA before flashing anything, and get rid of ROM Manager.