Okay, so I'm trying to fix a Samsung Galaxy S22 Ultra (SM-S908E) that's dead and won't boot. The user mentioned something about EDL mode and USB debugging. Let me think through how to approach this.

First, EDL stands for Emergency Download Mode. I remember that's a Qualcomm thing used for unbricking devices. But Samsung devices usually use Odin for flashing firmware instead of EDL. Wait, maybe this device is in a state where it can't enter download mode normally, so EDL is the last resort. But how do you even get into EDL on a Samsung? I thought you needed specific hardware tools or a deep flash cable.

The user mentioned "Dead Boot Repair By USB [DEBUG]". Maybe they tried some methods involving USB debugging, but if the phone is dead, USB debugging might not be enabled. Because if the phone can't boot, how would ADB or debugging be active? Unless they had USB debugging enabled before it died. But if it's completely dead, that might not help.

So steps I think: Check if the device can enter Download Mode (Odin mode) by holding Volume Down + Power or Volume Up + Down and connecting USB. If not, maybe EDL is needed. For EDL, you might need to short some test points on the motherboard to force it into EDL mode. But that's risky if you don't know the exact points. Maybe there's a tool like QFIL (Qualcomm Flash Image Loader) that can be used with the right firehose programmer file. But where to get the correct file for SM-S908E?

Wait, Samsung doesn't usually provide those files publicly. So maybe the user needs authorized software or an account. Alternatively, maybe using a combination of Odin and a patched firmware? Or maybe using a JTAG method? But that's even more involved.

Another thought: If the phone is recognized in EDL mode (QDLOADER 9008 in Device Manager), then you can try flashing it with the correct firmware. But without the specific Samsung EDL files, that's tough. Maybe check if the model-specific firmware is available from official sources. Or perhaps using a third-party service tool that has those files, but that's not legal unless you have authorization.

Alternatively, if the phone can be forced into Download Mode, then Odin is the way to go. Maybe using a combination of button presses, or using a USB jig to trigger Download Mode. A USB jig is a resistor between certain pins on the USB connector that forces the phone into download mode. For Samsung, it's usually a 300k ohm resistor between ID and GND. That might help if the buttons are broken.

But if the phone is completely unresponsive, maybe the battery is disconnected or dead. Opening the phone and checking the battery connection could be a step. However, that's not something a novice should do without proper tools.

Wait, the user mentioned "DEBUG" in the title. Maybe they have access to some debugging tools or logs. But if the phone is dead, how? Unless they have a rooted device and a custom recovery, but again, if it's dead, that's not helpful.

So possible steps:

1. Try to enter Download Mode: Vol Down + Power or Vol Up + Vol Down + Power while connecting to PC. If it works, use Odin to flash stock firmware.

2. If not, try EDL mode: This might require opening the device and shorting test points. Find the correct test points for SM-S908E. Maybe look for service manuals or teardown guides. Once in EDL, use QFIL with the right programmer file to flash. But where to get the files?

3. Check if the device is detected in EDL mode on the PC (QDLOADER 9008 COM port). If yes, search for SM-S908E EDL firmware or firehose file. If found, use QFIL to load the XML and flash.

4. If no EDL files are available, contact a repair shop that has access to Samsung tools like Octopus or Z3X, which might have the necessary files.

5. Alternatively, use a deep flash cable (a USB cable with modified wiring to force EDL mode). Maybe that's what the user meant by "USB DEBUG". But I'm not sure how that works exactly.

6. Check the battery: If the battery is completely dead, the phone won't turn on. Charge it for a while, or use a different charger/cable. If that doesn't work, maybe the battery is faulty and needs replacement.

7. Check for hardware issues: Water damage, physical damage, etc. Might require professional repair.

8. If all else fails, Samsung Service Center is the safest bet, but might be costly.

But the main issue is accessing EDL and having the right files. Without the firehose programmer, QFIL won't work. Samsung doesn't release those publicly, so maybe only authorized repair centers have them. So the user might need to find a way to get into Download Mode or use a USB jig. Alternatively, some third-party websites claim to have EDL files, but they could be risky or malware.

Another angle: Sometimes, leaving the phone charging for a long time (several hours) can revive a completely drained battery. Maybe try that first.

So summarizing:

- Attempt standard Download Mode entry.

- If fails, try EDL via test points or deep flash cable.

- Use QFIL with correct files if possible.

- If no access to files, seek professional help.

- Check battery and charging components.

But since this is a Samsung, maybe using Odin is still the best approach. If the user can get into Download Mode, download the stock firmware from Sammobile or Frija, then flash with Odin. If not, then EDL is the way, but with the caveats mentioned.