That's a stinker!!! If the sketches and other content are important, I'd consider a recovery service. They can usually do wonders, especially if the board fried and the data on the platters is still intact. The better recovery service shops keep the boards from various models around for that reason, i.e. Attempt to recovery your data with a known-good board.
FWIW, if this was water related, I have had good luck saving electronic devices after water dunkings using a directed airflow dehumidifier. They get toasty but they also dry out well enough to attempt a recovery. Eventually, crystals + corrosion will kill the boards, however.