MacBook Pro Not Booting!

The MacBook Pro retina late 2013 a1398 emc 2674

It was typing \ character countineously.
Startup options stopped working, no boot menu etc.
Installed clover, which put macbook into startup chime reboot loop.

Ghostlyhaks has been resourceful! Thank you!
Used raspberry pi 3.
Downloaded bin file from ghostlyhaks repository.
Changed serial number. Erased EFI chip. Wrote modified bin file to EFI chip.

Now no startup chime loop. Startup options working. Could install Windows 10 when macos installation got stuck at progress bar. No more repeat \ key, so keyboard is fine.
But unable to install macos successfully.
Also startup chime comes 20 seconds after power key pressed.
Kindly please guide!
Thanks!

NVRAM & SMC reset already tried.

Well MacBook booting but macos not )

Not getting which ME region file to use, ME analyser link on guide page on ghostlyhaks is dead.

Looks like I need clean ME 9.0.5.1367 file, not on win-raid list

could not find clean ME region 9.0.5.1367
used ME region code from original dump.
macbook is working perfectly now.

Vin,
I have the exact same issue with my MacBook Pro retina (mid-2012) A1398.
Clover put my MBP in an infinite boot-chime loop.

When you flashed the EFI-ROM did you use a SOIC8 clip connected directly to the EFI-ROM and Raspberry Pi? OR did you use an Easy Flash Adapter?

Also when you flashed the ROM with one downloaded from the repository, was the only thing you changed the Serial Number?

I used Raspberry Pi & this clip "Programmer Testing Clip SOP8 SOP SOIC 8 SOIC8 DIP8 DIP 8 Pin IC Test Clamp" soldered wires to top pins.
www.aliexpress.com/item/Free-shipping-Programmer-Testing-Clip-SOP8-SOP-SOIC-8-SOIC8-DIP8-DIP-8-Pin-IC-Test/32615107596.html
I took EFI-ROM from repository, changed serial number. But still macbook was unable to finish booting process from even macos bootable USB.
Then I tried to find clean ME region, but I could not find at win-raid list. So I copied ME region from original dump of my EFI, which I had backed up earlier put in serial modified EFI-ROM. Then burned it to EFI chip & everything worked!

I got my RPi today and was able to successfully pull 3 reads and made a backup of my corrupted ROM.

Now to find a good ROM, change the serial, and flash it back into my MBP.

Do you know if it matters is the specs of the ROM i find don't quite match my MacBook?
I did a post here about it--> ghostlyhaks.com/forum/n00b-z0n3/1544-specs-for-firmware-dump-request

Also what to you mean by a 'clean ME region?'

I think ROM should match EMC number (from bottom of macbook)
ROM you mentioned in other post should work.
About ME Region read here : www.ghostlyhaks.com/blog/apple-efi/25-clean-me-region
I had put SN modified ROM, but I had issue with booting macbook or installing new macOS, hence I realized I need to change ME region data too.