M8 Bad Flash. Is it dead?

[Ballz2k7]

I flashed my M8 a while ago with the finless rom, everything works great. I passed the item number I used to a friend and he bought 2 of the same item. So when they came I flashed the first with finless thinking it was the same as mine, it wasnt. Inside the box is a board marked M8 V8_1 20150422 (i think thats the date, its back together now.).
So looks like my seller changed supplier or something as the box externally is exactly the same as mine but not internally.

The box power led does not light
The optical port has no activity
I have tried numerous uboot's and the card maker and nothing recovers it. It seems the box is completely dead.
I have tried soldering the link between the usb and hdmi ports, and tried connecting USB, the pc doesnt even detect it. Is a portable hard drive cable (USB A to USB A) the same as the cable required?

Can anyone help me to recover this box?

Thanks in advance.

[Donovan2123]

Usb a to USB a is what you need along with the USB burning software and the correct firmware

Sent from my D6603 using Tapatalk

[Donovan2123]

This firmware, extract it and flash it using usb burning tool with erase all selected, erase bootloader and reset after succes. Make sure you put box in to otg mode by poking something in av port and holding button inside whilst you power on device

https://mega.nz/#!dkhXnKqJ!oILur-l9tv7J4BvXCBfbSHIwmRqHGRCpY4gqxVv0hHY

Sent from my D6603 using Tapatalk

[Ballz2k7]

I have tried a few usb a to a cables, both with the otg link and without, i hold the button and plug in the power but nothing happens, pc doesnt detect a usb device, no power led on box. Its just like its completely dead. All i did was flash it with the finless rom via SD card. I would have thought the recovery would still be there, strange that the box power led doesnt even light up, If i plug in a lan cable and put the power in the lan lights come on, flash a few times, then go off and do the same again. Theres definately power to the box. Any ideas how I can get it detected. Im using Windows 10 x64, the driver says installed on the usb burning tool. Says world cup driver installed.

[Ballz2k7]

I tried a usb stick in the ports too and the activity light doesnt come on, so no usb activity or power. Sure the drive i tried lights up once its powered.
Heres a pic of the pcb. I have shorted the link again for the OTG and I have made an A to A cable from 2 scrap cables from schematics found, matching colours it said. Still no detection in pc.
On the right of the pic theres 4 pins on the board. Are these the serial ports for console access on the CPU?

[Donovan2123]

Maybe you have incorrect drivers installed. You may need to manually install correct driver. You have to hold down button in av port whilst applying power to box then the USB burning software should say device connected

Sent from my D6603 using Tapatalk

[Donovan2123]

Also mine was like yours but computer would recognise box even thou box looked dead ie no lights etc. I just held down button in av port whilst applying power to box

Sent from my D6603 using Tapatalk

[jimmyjahooha]

where do i get drivers for my pc to recognise the M8 when i plug in usb?