diff --git a/lib/websafe/fetch-easyeda-json.ts b/lib/websafe/fetch-easyeda-json.ts
index 3ccfb791..945fdd02 100644
--- a/lib/websafe/fetch-easyeda-json.ts
+++ b/lib/websafe/fetch-easyeda-json.ts
@@ -107,12 +107,12 @@ export async function fetchEasyEDAComponent(
   })
 
   if (!searchResponse.ok) {
-    throw new Error("Failed to search for the component")
+    throw new Error(`Failed to search for component ${jlcpcbPartNumber} from EasyEDA API`)
   }
 
   const searchResult = await searchResponse.json()
   if (!searchResult.success || !searchResult.result.lists.lcsc.length) {
-    throw new Error("Component not found")
+    throw new Error(`Component with JLCPCB part number ${jlcpcbPartNumber} not found in EasyEDA database. This part may exist on JLCPCB but lacks EasyEDA footprint data.`)
   }
 
   const bestMatchComponent =
@@ -133,7 +133,7 @@ export async function fetchEasyEDAComponent(
   })
 
   if (!componentResponse.ok) {
-    throw new Error("Failed to fetch the component details")
+    throw new Error(`Failed to fetch component details for ${jlcpcbPartNumber} from EasyEDA API`)
   }
 
   const componentResult = await componentResponse.json()
diff --git a/tests/fetch-tests/c9900037709.test.ts b/tests/fetch-tests/c9900037709.test.ts
new file mode 100644
index 00000000..f9e04eab
--- /dev/null
+++ b/tests/fetch-tests/c9900037709.test.ts
@@ -0,0 +1,8 @@
+import { it, expect } from "bun:test"
+import { fetchEasyEDAComponent } from "lib/websafe/fetch-easyeda-json"
+
+it("should throw descriptive error for C9900037709 (not in EasyEDA database)", async () => {
+  await expect(fetchEasyEDAComponent("C9900037709")).rejects.toThrow(
+    "Component with JLCPCB part number C9900037709 not found in EasyEDA database",
+  )
+})