mobile

Hi.
I'm a complete noob, but I have spent weeks reading the various forums, and pretty sure no-one has answered my question elsewhere. Thanks in advance for any help pointing me in the right direction.

I have a brand new Samsung Galaxy Trend Plus GT-S7580L that I hard bricked trying to flash a custom ROM (solaris trend by pollog09) using CWM recovery, superSU root and Odin to flash. (I had previously successfully flashed Sandpox's cyanogen mod, successfully, but it was very unstable) I have since replaced the phone and don't need it, but I want to learn this stuff.

Phone is hard bricked: No vibrate, no LEDs, no boot, no download mode, no recovery mode, no recognition by PC ( linux / win). (Battery is fine, and appears to charge when in phone and connected to wall charger)

I have tried to enter recovery mode with USB jig - no response at all (jig works in other phone)
I have tried to create a debrick image file to try boot from SD card - not sure if I did this correctly:
- I installed CWM recovery 6.0.3.7 onto my new, identical phone, copied the T999_Partial_Sys_Dump_for_debrick.zip file from " [HARD BRICK ?] - I919x - Make your debrick.img and have it on extSdCard by security " as is onto an SD card, booted into recovery and installed it from SD card. It seemed to work and generated a debrick.img' file. i then used win32diskimager to write this to a 4GB SD card - i could only source a class 4 4GB card (no-one makes small SD cards anymore, and I don't think they ever had C10 ones) I tried this debrick image on SD card (as well as on 16GB C10 SD card) in my bricked phone - nothing. Tried numerous times and numerous rewrites (>20)

Q1: Did I go about making a debrick.img file correctly?
Q2: Does anyone have a debrick image of Samsung Galaxy trend Plus GT-S7580L available for me to try?
Q3: Are there any other options other than a paid for JTAG? How likely is it JTAG will work
Q4: Are there DIY JTAG solutions? - I'm prepared to sacrifice the phone, do some soldering?

Thanks