Repairing a damaged Mega

[nnnooo]

I accidentally damaged my Arduino Mega connecting the VCC to GND for a split second.
Then I read somewhere that probably the fried component would be the 5V voltage regulator, which was in fact burnt.
I replaced that voltage regulator and the board came alive again (sort of ....)
When I connect it using a USB cable the POWER LED lights up for a second or so and then slowly shuts down with the whole board.
I found out that the Fuse becomes really hot, at least 80 degrees Celsius.

So, I figure the fuse is shutting down the board, but I am not sure if there is a problem with the fuse itself or if it is something else that is short circuiting the board and the fuse is just doing its job.

Below is a picture of my board, not an original unfortunately.
The AMS1117 is the voltage reg I replaced, the component beside it (with the code 5) is the fuse.

I run out of ideas of what else to test, can someone suggest something I could do please?
Thanks

[J-M-L]

@nnnooo

connecting the VCC to GND for a split second

that's probably a split second too long... I would not trust that board any more even if it were to kinda work. You would be in for frustrating debug sessions later on when something will not work as expected and it will be hard to track....

➜ I'd say it's unfortunately time to recycle... Price to pay for learning...

[ruilviana]

This circuit also increases the MOSFET T1 which may be damaged.
See the diagrams below.