Geeetech

I just bought a GT 2560 and plugged it into a 24v power supply. Bang! The PSU fizzled out.

Now the board won't recognise when plugged into the PC but the lights come on and it sends power to the LCD (Just a green light).

I've plugged it back into the 12V power suplply and checked the voltage on the 2 fuses next to the power input, both are reading 12v.

Is there any way of salvaging this board? If anyone can help I'd really appreciate it!

It looks bad ...

Have you seen traces of charring and scorching the electronic components?
There is a high probability that the stabilizer on the controller board is destroyed.
And what else - it is not known.
Try to measure the voltages behind the 5V and 3V3 stabilizers.
If these voltages are incorrect, more components will be destroyed.

Sorry for my ignorance but should I be measuring ground to 5v and then ground to 3v3? What should those readings be? plugged into usb or 12v PSU?

[quote=Volume3k post_id=83923 time=1524730104 user_id=64588]
Sorry for my ignorance but should I be measuring ground to 5v and then ground to 3v3?
...
[/quote]

Yes
You can also try zero potential from the metal body of the USB socket.

[quote=Volume3k post_id=83923 time=1524730104 user_id=64588]
...
What should those readings be? plugged into usb or 12v PSU?
[/quote]

It's best to unplug the USB cable and run the printer from your power supply.