[Q] [HELP] Semi-bricked Samsung Smartphone - Android Q&A, Help & Troubleshooting

Hello XDA, I've been trying to solve this problem on my own for months now, but I haven't been successful, so I'm posting now in the hopes of having someone help.
About three months ago, I was browsing through my Tumblr feed when all of a sudden, my phone (a Samsung Galaxy Express, GT-I8730) shut off on its own. It wouldn't turn back on.
So of course I started to panic, but I tried plugging it into a PC. Windows found it as something like Qualcomm QHSUSB Download Mode. I did some research, and came upon @darkspr1te's "brixfix" tool, which I modified to work with my phone. I tried using it to no avail, so I did even more research. Turns out this happens to the S3 a lot (something about a bug in the eMMC firmware?), and people have recovered from it by using a special SD card onto which a dump of working bootloaders from another exact same device is copied.
So I tried that method, asked for a bootloader dump from one of my fellow I8730 users here on XDA, and burned the dump onto my spare 8GB Class 2 SD card. (I've read somewhere that one must use Class 10, but I can't afford to buy a new card. I later read on the same forum that slower, smaller cards are fine as long as they are able to contain the first 200MB of the bootloader dump.
I popped the card into the phone, switched it on, and it greeted me with this screen:
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
I assumed that this was normal, and so proceeded to Odin-flash the bootloaders (aboot, sbl1-3, tz) and the whole system (system, boot, recovery, modem, hidden, cache) onto the phone. It rebooted and hung at the splash screen, so I rebooted it into recovery mode; thinking that the ROM must have gotten corrupted somehow.
However, when I would normally see the recovery screen, Odin Mode greeted me with the message
Could not do normal boot.
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Click to collapse
Followed by the usual Odin info:
ODIN MODE
CUSTOM BINARY DOWNLOAD: Yes (1 counts)
CURRENT BINARY: Custom
SYSTEM STATUS: Custom
QUALCOMM SECUREBOOT: ENABLE
Click to expand...
Click to collapse
I tried flashing SYSTEM again at this point, but Odin Mode gave me
ODIN: flash read failure
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Click to collapse
and rebooted. I put it in Download Mode again, scoured the internet for a PIT file, and tried repartitioning; to which Odin Mode responded with
SECURE CHECK FAIL: PIT
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Click to collapse
I don't have the money for a new phone, let alone a JTAG box, so I'm at a loss as to what to do next. (And someone just released a working Lollipop ROM for my device, so I'm really excited to get this thing to work again. :good
My device info (accurate as of the last time I was able to use it properly):
ROM: CyanogenMod 11.0 (M8)
Kernel: 3.4.0 CM stock
Region: XSP (I8730DXAMC3, I8730OLBAMC3)
Click to expand...
Click to collapse
I also opened it up (it's out of warranty) and listed down all info I could find:
Component Type: Name [Associated Markings]
Digital Signal Processor: QCOM WCD9304 [OVV NFK60000 A824801]
Accelerometer: Invensense MPU-6051M
eMMC: SanDisk [SDIN7DU2-8G 3067DFW46OPP CHINA]
NFC Controller: NXP PN547 [47601 4T35109 N+ D12521Y]
RAM: SAMSUNG [310 K4P8G304EB-GGC2 GKA6579P]
GPIO: QCOM PM8917 [OVV 3R29988 AU25201 07]
WLAN/BT: Broadcom BCM7320 [KY4U]
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Click to collapse
Any help would be appreciated.​