[Help] Akai Tab-7800 stuck at android logo

Hello everyone!

This will be a bit long but here is my problem.
I got aAkai Tab-7800 that was dropped by a kid when he was playing with it. Since than it won't go past the android logo when booting. I took off only the backcover but I didn't see any damage there.
I tried to go into the recovery menu but when I try to start the tablet with the volume + and power button it won't start.

Tablet specs:
-Android 4.0.4
-Allwinner A13
- 512 MB RAM

Since my Concorde tablet also has an Allwinner cpu I tried PhoenixSuit because thats what I used to flash mine.
The tablet is still "alive" since it can communicate with the pc and got these info from it:
- Model: nuclear-evb
- Rom version: nuclear_evb-eng 4.0.4 IMM76D 20130115 test-keys
- Android version: 4.0.4
- Chip type: nuclear
- Kernel: Linux version 3.0.8+ (along@along) (gcc version 4.5.1 (Sourcery G++ Lite 2010.90-50)

When I tried to use the "recovery mode" in Phoenix, the tablet only restarted.

Now my question is what do you suggest? Shall I try to flash a new rom onto it and if yes which one? Or is there something else I could try?

Thank you for your answares in advance.