PFW-1336

The following situation is now fixed, steps:
1. Load filament through LCD
2. Load to nozzle through LCD
3. Before filament reaches Fsensor => turn off the printer
4. Wait a few seconds and then turn the printer on again
5. Start a print through the SD card
6. Printer will unload and then re-load the filament

Previously in step 6, the printer would start a print without any
filament loaded.

Firmware/Marlin_main.cpp

@@ -5448,24 +5448,32 @@ eeprom_update_word((uint16_t*)EEPROM_NOZZLE_DIAMETER_uM,0xFFFF);
 	### M24 - Start SD print <a href="https://reprap.org/wiki/G-code#M24:_Start.2Fresume_SD_print">M24: Start/resume SD print</a>
     */
     case 24:
-	  if (isPrintPaused)
-          lcd_resume_print();
-      else
+    if (isPrintPaused)
+      lcd_resume_print();
+    else
+    {
+      if (!card.get_sdpos())
       {
-          if (!card.get_sdpos())
-          {
               // A new print has started from scratch, reset stats
               failstats_reset_print();
               sdpos_atomic = 0;
 #ifndef LA_NOCOMPAT
-              la10c_reset();
+        la10c_reset();
 #endif
-          }
+      }
 
-          card.startFileprint();
-          starttime=_millis();
+      card.startFileprint();
+      starttime=_millis();
+      if (MMU2::mmu2.Enabled())
+      {
+        if (MMU2::mmu2.FindaDetectsFilament() && !fsensor.getFilamentPresent())
+        { // Filament only half way into the PTFE. Unload the filament.
+          MMU2::mmu2.unload();
+          // Tx and Tc gcodes take care of loading the filament to the nozzle.
+        }
       }
-	  break;
+    }
+    break;
 
     /*!
 	### M26 - Set SD index <a href="https://reprap.org/wiki/G-code#M26:_Set_SD_position">M26: Set SD position</a>

Firmware/Tcodes.cpp

@@ -45,7 +45,7 @@ void TCodes(char *const strchr_pointer, uint8_t codeValue) {
 
     if (IsInvalidTCode(strchr_pointer, index)){
         TCodeInvalid();
-    } /*else if (strchr_pointer[index] == 'x'){
+    } else if (strchr_pointer[index] == 'x'){
         // load to bondtech gears; if mmu is not present do nothing
         if (MMU2::mmu2.Enabled()) {
             MMU2::mmu2.tool_change(strchr_pointer[index], choose_menu_P(_T(MSG_CHOOSE_EXTRUDER), _T(MSG_EXTRUDER)));
@@ -53,9 +53,9 @@ void TCodes(char *const strchr_pointer, uint8_t codeValue) {
     } else if (strchr_pointer[index] == 'c'){
         // load from bondtech gears to nozzle (nozzle should be preheated)
         if (MMU2::mmu2.Enabled()) {
-            MMU2::mmu2.tool_change(strchr_pointer[index], 0);
+            MMU2::mmu2.tool_change(strchr_pointer[index], MMU2::mmu2.get_current_tool());
         }
-    }*/ else {
+    } else {
         SChooseFromMenu selectedSlot;
 //        if (strchr_pointer[index] == '?')
 //            selectedSlot = TCodeChooseFromMenu();