Thanks alot for the tip regarding the battery - will definetly try this.
I downloaded the CID49 Pack and gonna try Far+SEFP.
For hardware I'm using a DCU-60 USB cable, and a laptop with the Sony Ericsson USB Flash drivers installed.
Will keep you updated on how things're going.
Cheers! :)
...
Note: Actually managed to get some info out of the phone - so I guess it's not a total goner, even if it refuses to start. Here's the info I got from PhoneXS++:
19:10:39| PORT STATUS: ACTIVE
19:10:39| Baseband ID: 8040
19:10:39| Hardware Platform: db2010 Marita compact
19:10:39| Protocol Version: 3.1
19:10:39| Sending loaders\db2010_cid00_prodid_p3k.bin...
19:10:39| This is a PRODUCTION_ID loader
19:10:39| Activating GDFS...
19:10:40| Warning: IMEI name does not match GDFS name (IMEI:NULL GDFS:Z558)
19:10:40| ...using GDFS name
19:10:40| ++++++++++++++++++++++++++++++++++
19:10:40| PHONE INFO
19:10:40| ++++++++++++++++++++++++++++++++++
19:10:40| DBID: db2010
19:10:40| OTP CID: 49
19:10:40| EROM CID: 49
19:10:40| EROM color: Brown
19:10:40| IMEI: 00460102xxxxxx
19:10:40| Phone: Z558
19:10:40| Operator: CHINA
19:10:40| CDA: CDA102587/203 R8A
19:10:40| Firmware: R4FA006
19:10:40| EROM: n/a
My guess as a total newbie to this flashing-thing would be that the last line (EROM: n/a) could be the reason why the phone refuses to start, right? The natural question is: how do I resolve it? :)
Thanks for all the help so far!