diff --git a/Firmware/Marlin_main.cpp b/Firmware/Marlin_main.cpp
index f2b190670..4f5a931b6 100644
--- a/Firmware/Marlin_main.cpp
+++ b/Firmware/Marlin_main.cpp
@@ -865,23 +865,23 @@ void show_fw_version_warnings() {
 	lcd_update_enable(true);
 }
 
-//try to check if firmware is on right type of printer 
-void check_if_fw_is_on_right_printer(){
-  #ifdef FILAMENT_SENSOR
-    swi2c_init();
-    uint8_t pat9125_detected = swi2c_readByte_A8(PAT9125_I2C_ADDR,0x00,NULL);
-    uint8_t ir_detected = !(PIN_GET(IR_SENSOR_PIN)); //will return 1 only if IR can detect filament in bondtech extruder so this may fail even when we have IR sensor
-  
+//! @brief try to check if firmware is on right type of printer
+static void check_if_fw_is_on_right_printer(){
+#ifdef FILAMENT_SENSOR
     #ifdef IR_SENSOR
+    swi2c_init();
+    const uint8_t pat9125_detected = swi2c_readByte_A8(PAT9125_I2C_ADDR,0x00,NULL);
       if (pat9125_detected){
         lcd_show_fullscreen_message_and_wait_P(_i("MK3S firmware detected on MK3 printer"));}
-    #endif
+    #endif //IR_SENSOR
 
     #ifdef PAT9125
+      //will return 1 only if IR can detect filament in bondtech extruder so this may fail even when we have IR sensor
+      const uint8_t ir_detected = !(PIN_GET(IR_SENSOR_PIN));
       if (ir_detected){
         lcd_show_fullscreen_message_and_wait_P(_i("MK3 firmware detected on MK3S printer"));}
-    #endif
-  #endif
+    #endif //PAT9125
+#endif //FILAMENT_SENSOR
 }
 
 uint8_t check_printer_version()
@@ -9652,7 +9652,7 @@ void marlin_wait_for_click()
         manage_inactivity(true);
         lcd_update(0);
     }
-    KEEPALIVE_STATE(busy_state);
+    KEEPALIVE_STATE(busy_state_backup);
 }
 
 #define FIL_LOAD_LENGTH 60
diff --git a/Firmware/menu.cpp b/Firmware/menu.cpp
index e84043540..2534b43a2 100755
--- a/Firmware/menu.cpp
+++ b/Firmware/menu.cpp
@@ -174,7 +174,7 @@ static void menu_draw_item_puts_P(char type_char, const char* str)
     lcd_printf_P(PSTR("%c%-18.18S%c"), (lcd_encoder == menu_item)?'>':' ', str, type_char);
 }
 
-static int menu_draw_item_puts_P(char type_char, const char* str, char num)
+static void menu_draw_item_puts_P(char type_char, const char* str, char num)
 {
     lcd_set_cursor(0, menu_row);
     lcd_printf_P(PSTR("%c%-.16S "), (lcd_encoder == menu_item)?'>':' ', str);
diff --git a/Firmware/mmu.cpp b/Firmware/mmu.cpp
index 783564329..0c1279964 100644
--- a/Firmware/mmu.cpp
+++ b/Firmware/mmu.cpp
@@ -965,7 +965,7 @@ void display_loading()
 	}
 }
 
-void extr_adj(int extruder) //loading filament for SNMM
+void extr_adj(uint8_t extruder) //loading filament for SNMM
 {
 #ifndef SNMM
     MmuCmd cmd = MmuCmd::L0 + extruder;
diff --git a/Firmware/mmu.h b/Firmware/mmu.h
index a7da0c2d9..0f8784ba7 100644
--- a/Firmware/mmu.h
+++ b/Firmware/mmu.h
@@ -103,7 +103,7 @@ extern void extr_mov(float shift, float feed_rate);
 extern void change_extr(int extr);
 extern int get_ext_nr();
 extern void display_loading();
-extern void extr_adj(int extruder);
+extern void extr_adj(uint8_t extruder);
 extern void extr_unload();
 //-//
 extern void extr_unload_();
diff --git a/Firmware/ultralcd.h b/Firmware/ultralcd.h
index 84988c588..365f17977 100644
--- a/Firmware/ultralcd.h
+++ b/Firmware/ultralcd.h
@@ -129,7 +129,6 @@ void lcd_commands();
 
 
 void change_extr(int extr);
-void extr_adj(int extruder);
 
 #ifdef SNMM
 void extr_unload_all();