[LG Optimus L9 P760, P765, P768, P769] dany123i:
Hello xda,

tldr: i can only use fastboot right now, what do i flash to get a working recovery/sw upgrade mode/rom/something?

I got a LG P760 a year ago from a friend to have as backup phone and I tried then to root and put a custom rom but something went wrong and got the security error. After some more tries with fastboot the phone wouldn't even turn on so i gave up on it.

Now my main phone died and i wanted to fix and use this lg for a while but i can't seem to get anywhere after many many hours of trying.

As i said in title there's nothing appearing on screen at any point, no recovery, no lg logo, no fastboot text (as i've seen in some screenshot around here), no sw upgrade screen. The most i got out of it was the back/menu buttons to light up when using the omap4boot with option "[2] p920 - Optimus 3D (P920)" from here.

The only consistent answer i get is when using omap4boot with option " [3] p940 - Prada 3.0 (P940)": i can see my device for about 5-10 mins in fastboot devices list and can flash stuff with it.

//fastboot devices correct:

C:\omap4boot>start_fastboot.bat

--------------------------------------------
OMAP4boot for P920/P720/SU540/SU760/SU870
--------------------------------------------
by wkpark at gmail dot com

[1] cx2 - Optimus 3D Cube (SU870/P720)
[2] p920 - Optimus 3D (P920)
[3] p940 - Prada 3.0 (P940)
[4] su540 - Prada 3.0 (SU540/KU5400)
[5] su760 - Optimus 3D (SU760)
[x] exit
-------------------------------------------

Select device and <ENTER> 3
p940 selected

waiting for OMAP44xx device...

Device descriptor:
bLength = 18
bDescriptorType = 1
bcdUSB = 528
bDeviceClass = 255
bDeviceSubClass = 255
bDeviceProtocol = 255
bMaxPacketSize0 = 64
idVendor = 451
idProduct = D00F
bcdDevice = 0
iManufacturer = 33
iProduct = 37
iSerialNumber = 0
bNumConfigurations = 1
reading ASIC ID
usb_write 4
usb_read 81
[*] read 0 bytes
NumOfSubblocks: 0x5
Subblock ID: 0x1
Subblock Size: 0x5
CH enabled: 0x7
ROM revision: 0x4
Checksum Subblock: 0x15
CHIP: 4430
IDEN: 211795482064db2dd4c70281fb39c14018973f30
MPKH: 5f4092eccddf90fa43f546adf89508b31b9c74795e9516194c0ea6412fdcb7f6
CRC0: 9c669ad9
CRC1: 682adccf
sending 2ndstage to target... f0030002
usb_write 4
usb_write 4

wait 5-seconds...

[*] msg size = 4
usb_write 21552
[*] data size = 21552
usb_close

Reopen usb...

Device descriptor:
bLength = 18
bDescriptorType = 1
bcdUSB = 528
bDeviceClass = 255
bDeviceSubClass = 255
bDeviceProtocol = 255
bMaxPacketSize0 = 64
idVendor = 451
idProduct = D00F
bcdDevice = 0
iManufacturer = 33
iProduct = 37
iSerialNumber = 0
bNumConfigurations = 1
waiting for 2ndstage response...
usb_read 4
usb read = aabbccdd
accepted 2ndstage response
sending image to target...
size = 246272
usb_write 4
usb_write 246272
** Done **
------------------------------
Please remove USB cable
and wait until LG Logo on
then reconnent USB cable again
------------------------------

fastboot devices (y/N) ? and press <ENTER> n

ls: resigned/p940-MLO*.bin: No such file or directory

Do you want to replace u-boot (y/N) ?n
ls: cwm/p940-*.img: No such file or directory
Press any key to continue . . .
01608CBF0800A01E fastboot
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\omap4boot>
C:\omap4boot>fastboot devices
01608CBF0800A01E fastboot

C:\omap4boot>

Using the lelus's fastboot zip i can get as far as sending "u-boot", where it freezes both on option "2. P760 - Flash ICS xloader and uboot" and "6. P760 - Flash JB xloader and uboot (p765 and p768 compatible)":

//lelus fastboot for p760:
//option 2

ECHO is off.
Plug USB cable
wait 4 seconds and put battery back in.
waiting for OMAP44xx device...

Device descriptor:
bLength = 18
bDescriptorType = 1
bcdUSB = 528
bDeviceClass = 255
bDeviceSubClass = 255
bDeviceProtocol = 255
bMaxPacketSize0 = 64
idVendor = 451
idProduct = D00F
bcdDevice = 0
iManufacturer = 33
iProduct = 37
iSerialNumber = 0
bNumConfigurations = 1
reading ASIC ID
usb_write 4
usb_read 81
[*] read 0 bytes
NumOfSubblocks: 0x5
Subblock ID: 0x1
Subblock Size: 0x5
CH enabled: 0x7
ROM revision: 0x4
Checksum Subblock: 0x15
CHIP: 4430
IDEN: 211795482064db2dd4c70281fb39c14018973f30
MPKH: 5f4092eccddf90fa43f546adf89508b31b9c74795e9516194c0ea6412fdcb7f6
CRC0: 9c669ad9
CRC1: 682adccf
sending 2ndstage to target... f0030002
usb_write 4
usb_write 4

wait 5-lelelel...

[*] msg size = 4
usb_write 21552
[*] data size = 21552
usb_close

Reopen usb...

Device descriptor:
bLength = 18
bDescriptorType = 1
bcdUSB = 528
bDeviceClass = 255
bDeviceSubClass = 255
bDeviceProtocol = 255
bMaxPacketSize0 = 64
idVendor = 451
idProduct = D00F
bcdDevice = 0
iManufacturer = 33
iProduct = 37
iSerialNumber = 0
bNumConfigurations = 1
waiting for 2ndstage response...
usb_read 4
usb read = aabbccdd
accepted 2ndstage response
sending image to target...
size = 246272
usb_write 4
usb_write 246272
** Done **
< waiting for device >
sending 'x-loader' (384 KB)...
OKAY [ 0.199s]
writing 'x-loader'...
OKAY [ 2.840s]
finished. total time: 3.040s
sending 'u-boot' (1024 KB)...

//after 2 mins i disconnect phone

FAILED (status read failed (Too many links))
finished. total time: 114.895s
Done
Press any key to continue . . .

///option 6
ECHO is off.
Plug USB cable
wait 4 seconds and put battery back in.
waiting for OMAP44xx device...

Device descriptor:
bLength = 18
bDescriptorType = 1
bcdUSB = 528
bDeviceClass = 255
bDeviceSubClass = 255
bDeviceProtocol = 255
bMaxPacketSize0 = 64
idVendor = 451
idProduct = D00F
bcdDevice = 0
iManufacturer = 33
iProduct = 37
iSerialNumber = 0
bNumConfigurations = 1
reading ASIC ID
usb_write 4
usb_read 81
[*] read 0 bytes
NumOfSubblocks: 0x5
Subblock ID: 0x1
Subblock Size: 0x5
CH enabled: 0x7
ROM revision: 0x4
Checksum Subblock: 0x15
CHIP: 4430
IDEN: 211795482064db2dd4c70281fb39c14018973f30
MPKH: 5f4092eccddf90fa43f546adf89508b31b9c74795e9516194c0ea6412fdcb7f6
CRC0: 9c669ad9
CRC1: 682adccf
sending 2ndstage to target... f0030002
usb_write 4
usb_write 4

wait 5-lelelel...

[*] msg size = 4
usb_write 21552
[*] data size = 21552
usb_close

Reopen usb...

Device descriptor:
bLength = 18
bDescriptorType = 1
bcdUSB = 528
bDeviceClass = 255
bDeviceSubClass = 255
bDeviceProtocol = 255
bMaxPacketSize0 = 64
idVendor = 451
idProduct = D00F
bcdDevice = 0
iManufacturer = 33
iProduct = 37
iSerialNumber = 0
bNumConfigurations = 1
waiting for 2ndstage response...
usb_read 4
usb read = aabbccdd
accepted 2ndstage response
sending image to target...
size = 246272
usb_write 4
usb_write 246272
** Done **
< waiting for device >
sending 'x-loader' (384 KB)...
OKAY [ 0.200s]
writing 'x-loader'...
OKAY [ 2.840s]
finished. total time: 3.041s
sending 'u-boot' (1024 KB)...
FAILED (status read failed (Too many links))
finished. total time: 49.719s
Done
Press any key to continue . . .

So right now i need help for the next steps, most of the guides i've found require sw upgrade mode or recovery to continue after fastboot phase but i can't get into anything. I don't even know what rom/kernel/recovery i had last time, what should i search and flash now? (boot/kernel/rom/recovery/??).