🔧 Assert Probe Temp Comp requirements (#24468)

Marlin/src/inc/Conditionals_adv.h

   #endif
 #endif
 
-// Probe Temperature Compensation
-#if !TEMP_SENSOR_PROBE
-  #undef PTC_PROBE
-#endif
-#if !TEMP_SENSOR_BED
-  #undef PTC_BED
-#endif
-#if !HAS_EXTRUDERS
-  #undef PTC_HOTEND
-#endif
 #if ANY(PTC_PROBE, PTC_BED, PTC_HOTEND)
   #define HAS_PTC 1
 #endif

Marlin/src/inc/SanityCheck.h

     #endif
   #endif
 
-  #ifdef PTC_PROBE_START
-    constexpr auto _ptc_sample_start = PTC_PROBE_START;
-    constexpr decltype(_ptc_sample_start) _test_ptc_sample_start = 12.3f;
-    static_assert(_test_ptc_sample_start != 12.3f, "PTC_PROBE_START must be a whole number.");
-  #endif
-  #ifdef PTC_PROBE_RES
-    constexpr auto _ptc_sample_res = PTC_PROBE_RES;
-    constexpr decltype(_ptc_sample_res) _test_ptc_sample_res = 12.3f;
-    static_assert(_test_ptc_sample_res != 12.3f, "PTC_PROBE_RES must be a whole number.");
-  #endif
-  #ifdef PTC_BED_START
-    constexpr auto _btc_sample_start = PTC_BED_START;
-    constexpr decltype(_btc_sample_start) _test_btc_sample_start = 12.3f;
-    static_assert(_test_btc_sample_start != 12.3f, "PTC_BED_START must be a whole number.");
-  #endif
-  #ifdef PTC_BED_RES
-    constexpr auto _btc_sample_res = PTC_BED_RES;
-    constexpr decltype(_btc_sample_res) _test_btc_sample_res = 12.3f;
-    static_assert(_test_btc_sample_res != 12.3f, "PTC_BED_RES must be a whole number.");
-  #endif
-  #ifdef PTC_PROBE_TEMP
-    constexpr auto _btc_probe_temp = PTC_PROBE_TEMP;
-    constexpr decltype(_btc_probe_temp) _test_btc_probe_temp = 12.3f;
-    static_assert(_test_btc_probe_temp != 12.3f, "PTC_PROBE_TEMP must be a whole number.");
+  #if ENABLED(PTC_PROBE)
+    #if !TEMP_SENSOR_PROBE
+      #error "PTC_PROBE requires a probe with a thermistor."
+    #endif
+    #ifdef PTC_PROBE_START
+      constexpr auto _ptc_sample_start = PTC_PROBE_START;
+      constexpr decltype(_ptc_sample_start) _test_ptc_sample_start = 12.3f;
+      static_assert(_test_ptc_sample_start != 12.3f, "PTC_PROBE_START must be a whole number.");
+    #endif
+    #ifdef PTC_PROBE_RES
+      constexpr auto _ptc_sample_res = PTC_PROBE_RES;
+      constexpr decltype(_ptc_sample_res) _test_ptc_sample_res = 12.3f;
+      static_assert(_test_ptc_sample_res != 12.3f, "PTC_PROBE_RES must be a whole number.");
+    #endif
+    #if ENABLED(PTC_BED) && defined(PTC_PROBE_TEMP)
+      constexpr auto _btc_probe_temp = PTC_PROBE_TEMP;
+      constexpr decltype(_btc_probe_temp) _test_btc_probe_temp = 12.3f;
+      static_assert(_test_btc_probe_temp != 12.3f, "PTC_PROBE_TEMP must be a whole number.");
+    #endif
+  #endif
+
+  #if ENABLED(PTC_BED)
+    #if !TEMP_SENSOR_BED
+      #error "PTC_BED requires a bed with a thermistor."
+    #endif
+    #ifdef PTC_BED_START
+      constexpr auto _btc_sample_start = PTC_BED_START;
+      constexpr decltype(_btc_sample_start) _test_btc_sample_start = 12.3f;
+      static_assert(_test_btc_sample_start != 12.3f, "PTC_BED_START must be a whole number.");
+    #endif
+    #ifdef PTC_BED_RES
+      constexpr auto _btc_sample_res = PTC_BED_RES;
+      constexpr decltype(_btc_sample_res) _test_btc_sample_res = 12.3f;
+      static_assert(_test_btc_sample_res != 12.3f, "PTC_BED_RES must be a whole number.");
+    #endif
   #endif
+
   #if ENABLED(PTC_HOTEND)
     #if EXTRUDERS != 1
-      #error "PTC_HOTEND only works with a single extruder."
+      #error "PTC_HOTEND requires a single extruder."
     #endif
     #ifdef PTC_HOTEND_START
       constexpr auto _etc_sample_start = PTC_HOTEND_START;