diff --git a/bec_widgets/validation/monitor_config_validator.py b/bec_widgets/validation/monitor_config_validator.py
index 7d5dc353..5a92f7de 100644
--- a/bec_widgets/validation/monitor_config_validator.py
+++ b/bec_widgets/validation/monitor_config_validator.py
@@ -142,9 +142,9 @@ class PlotConfig(BaseModel):
         sources (list): A list of sources to be plotted on this axis.
     """
 
-    plot_name: Optional[str]
-    x_label: Optional[str]
-    y_label: Optional[str]
+    plot_name: Optional[str] = None
+    x_label: Optional[str] = None
+    y_label: Optional[str] = None
     sources: list = Field(default_factory=list)
 
     @field_validator("sources")
@@ -156,23 +156,11 @@ class PlotConfig(BaseModel):
             Source(**source)
             source_type = source.get("type", None)
 
-            # Check if source type provided
-            if source_type is None:
-                raise PydanticCustomError(
-                    "no_source_type", "Source type must be provided", {"wrong_value": source}
-                )
-
             # Check if source type is supported
             if source_type == "scan_segment":
                 validated_sources.append(SourceSegmentValidator(**source))
             elif source_type == "history":
                 validated_sources.append(SourceHistoryValidator(**source))
-            else:
-                raise PydanticCustomError(
-                    "unsupported_source_type",
-                    "Unsupported source type: '{wrong_value}'",
-                    {"wrong_value": source_type},
-                )
         return validated_sources
 
 
@@ -192,9 +180,9 @@ class PlotSettings(BaseModel):
     background_color: Literal["black", "white"] = "black"
     axis_width: Optional[int] = 2
     axis_color: Optional[str] = None
-    num_columns: int
-    colormap: str
-    scan_types: bool
+    num_columns: Optional[int] = 1
+    colormap: Optional[str] = "magma"
+    scan_types: Optional[bool] = False
 
 
 class DeviceMonitorConfig(BaseModel):
diff --git a/bec_widgets/widgets/monitor/monitor.py b/bec_widgets/widgets/monitor/monitor.py
index 9364bba1..8d89d9c6 100644
--- a/bec_widgets/widgets/monitor/monitor.py
+++ b/bec_widgets/widgets/monitor/monitor.py
@@ -163,6 +163,22 @@ CONFIG_WRONG = {
                 }
             ],
         },
+        {
+            "plot_name": "Gauss plots vs samx",
+            "x_label": "Motor X",
+            "y_label": "Gauss",
+            "sources": [
+                {
+                    "signals": {
+                        "x": [{"name": "samx", "entry": "samx"}],
+                        "y": [
+                            {"name": "samx"},
+                            {"name": "samy", "entry": "samx"},
+                        ],
+                    },
+                }
+            ],
+        },
     ],
 }
 
diff --git a/tests/test_validator_errors.py b/tests/test_validator_errors.py
index 7657b9cf..114b4cce 100644
--- a/tests/test_validator_errors.py
+++ b/tests/test_validator_errors.py
@@ -4,7 +4,7 @@ from pydantic import ValidationError
 from bec_widgets.validation.monitor_config_validator import (
     MonitorConfigValidator,
     Signal,
-    PlotAxis,
+    AxisSignal,
     PlotConfig,
 )
 
@@ -63,18 +63,43 @@ def test_plot_config_x_axis_signal_validation(setup_devices):
     # Setup a valid signal
     valid_signal = Signal(name="samx")
 
-    # Case with more than one signal for x-axis
-    plot_axis_multiple_signals = PlotAxis(
-        signals=[valid_signal, valid_signal], label="X Axis Label"
-    )
     with pytest.raises(ValidationError) as excinfo:
-        PlotConfig(
-            plot_name="Test Plot",
-            x=plot_axis_multiple_signals,
-            y=PlotAxis(signals=[valid_signal], label="Y Axis Label"),
-        )
+        AxisSignal(x=[valid_signal, valid_signal], y=[valid_signal, valid_signal])
 
     errors = excinfo.value.errors()
     assert len(errors) == 1
     assert errors[0]["type"] == "x_axis_multiple_signals"
     assert "There must be exactly one signal for x axis" in errors[0]["msg"]
+
+
+def test_plot_config_unsupported_source_type(setup_devices):
+    with pytest.raises(ValidationError) as excinfo:
+        PlotConfig(sources=[{"type": "unsupported_type", "signals": {}}])
+
+    errors = excinfo.value.errors()
+    print(errors)
+    assert len(errors) == 1
+    assert errors[0]["type"] == "literal_error"
+
+
+def test_plot_config_no_source_type_provided(setup_devices):
+    with pytest.raises(ValidationError) as excinfo:
+        PlotConfig(sources=[{"signals": {}}])
+
+    errors = excinfo.value.errors()
+    assert len(errors) == 1
+    assert errors[0]["type"] == "missing"
+
+
+def test_plot_config_history_source_type(setup_devices):
+    history_source = {
+        "type": "history",
+        "scanID": "valid_scan_id",
+        "signals": {"x": [{"name": "samx"}], "y": [{"name": "samx"}]},
+    }
+
+    plot_config = PlotConfig(sources=[history_source])
+
+    assert len(plot_config.sources) == 1
+    assert plot_config.sources[0].type == "history"
+    assert plot_config.sources[0].scanID == "valid_scan_id"