diff --git a/home.admin/00mainMenu.sh b/home.admin/00mainMenu.sh
index 2be5b5a..30a6475 100755
--- a/home.admin/00mainMenu.sh
+++ b/home.admin/00mainMenu.sh
@@ -69,12 +69,23 @@ fi
 if [ "${state}" = "presync" ]; then
   # stopping the pre-sync
   echo ""
-  echo "********************************************"
-  echo "Stopping pre-sync ... pls wait (up to 1min)"
-  echo "********************************************"
-  sudo -u root bitcoin-cli -conf=/home/admin/assets/bitcoin.conf stop
-  echo "bitcoind called to stop .."
-  sleep 50
+  # analyse if blockchain was detected broken by pre-sync
+  blockchainBroken=$(sudo tail /mnt/hdd/bitcoin/debug.log | grep -c "Please restart with -reindex or -reindex-chainstate to recover.")
+  if [ ${blockchainBroken} -eq 1 ]; then
+    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+    echo "Detected corrupted blockchain on pre-sync !"
+    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
+    echo "Deleting blockchain data ..."
+    echo "(needs to get downloaded fresh during setup)"
+    sudo rm -f -r /mnt/hdd/bitcoin
+  else
+    echo "********************************************"
+    echo "Stopping pre-sync ... pls wait (up to 1min)"
+    echo "********************************************"
+    sudo -u root bitcoin-cli -conf=/home/admin/assets/bitcoin.conf stop
+    echo "bitcoind called to stop .."
+    sleep 50
+  fi
 
   # unmount the temporary mount
   echo "Unmount HDD .."
diff --git a/home.admin/_bootstrap.sh b/home.admin/_bootstrap.sh
index c68a53a..2c29191 100644
--- a/home.admin/_bootstrap.sh
+++ b/home.admin/_bootstrap.sh
@@ -245,6 +245,8 @@ if [ ${hddIsAutoMounted} -eq 0 ]; then
     # check if pre-sync was already activated on last power-on
     #presyncActive=$(systemctl status bitcoind | grep -c 'could not be found')
     echo "starting pre-sync in background" >> $logFile
+    # make sure that debug file is clean, so just pre-sync gets analysed on stop
+    sudo rm /mnt/hdd/bitcoin/debug.log
     # starting in background, because this scripts is part of systemd
     # so to change systemd needs to happen after delay in seperate process
     sudo chown -R bitcoin:bitcoin /mnt/hdd/bitcoin 2>> $logFile