appliance-fault-diagnosis

name: appliance-fault-diagnosis description: Diagnose home appliance faults using local knowledge base before searching external sources version: 1.0.0 metadata: hermes: tags: [appliance, refrigerator, fault-codes, knowledge-base, troubleshooting]

Appliance Fault Diagnosis with Local Knowledge Base

When users report appliance problems (especially refrigerators), always check the local knowledge base first before searching externally.

Knowledge Base Location

~/mydocs/knowledgebase/

Available Resources

Text Files

• 家电维修.txt - Contains fault codes and descriptions

PDF Manuals (VERIFIED CONTENTS)

⚠️ Critical Lesson: PDF filenames may NOT match content (e.g., "RF8500" filename contains RF50DG5021 refrigerator manual). Always verify by extracting first few pages before referencing.

Workflow

Step 1: List Knowledge Base Contents

ls -la ~/hermes-agent/mydocs/knowledgebase/

Note: Path is ~/hermes-agent/mydocs/knowledgebase/ (relative to hermes-agent directory).

Step 2: Read Fault Code Reference (TEXT FILE FIRST)

cat ~/hermes-agent/mydocs/knowledgebase/家电维修.txt

Contains basic fault codes for refrigerators (C71, C72, C73, C76).

Step 3: Search PDF Manuals for Detailed Information

Install pymupdf if needed:

~/hermes-agent/venv/bin/python -m pip install pymupdf -q

Extract and verify PDF content (first 30 pages):

import pymupdf

# Use absolute path
doc = pymupdf.open("/home/user/hermes-agent/mydocs/knowledgebase/<filename>.pdf")

# Extract first 30 pages to identify content
text = ""
for i, page in enumerate(doc[:30]):
    text += f"\n=== 第 {i+1} 页 ===\n"
    text += page.get_text()

print(text[:15000])  # Limit output
print(f"\n\n总页数：{len(doc)}")

Search for specific content (error codes, symptoms):

import pymupdf

doc = pymupdf.open("/home/user/hermes-agent/mydocs/knowledgebase/<filename>.pdf")

# Search all pages for keywords
for i, page in enumerate(doc):
    text = page.get_text()
    if "高温" in text or "报警" in text or "错误" in text:
        print(f"\n=== 第 {i+1} 页 ===")
        print(text[:2000])

Extract specific sections (e.g., pages 39-46 for troubleshooting):

import pymupdf

doc = pymupdf.open("/home/user/hermes-agent/mydocs/knowledgebase/<filename>.pdf")

text = ""
for i, page in enumerate(doc[38:46]):  # Pages 39-46 (0-indexed)
    text += f"\n=== 第 {i+39} 页 ===\n"
    text += page.get_text()

print(text[:12000])

Step 4: Provide Troubleshooting Steps

From 家电维修.txt (basic fault codes):

From Refrigerator Manual (DA68-04798R-06) - Comprehensive Troubleshooting:

Samsung Customer Service: 400-810-5858 (all Samsung appliances)

Response Template

When user reports a fault code:

1. Confirm the fault code and its meaning from knowledge base
2. Provide step-by-step troubleshooting:
   • Check doors/seals
   • Check stored items (no hot food)
   • Check ventilation (no blockage)
   • Check temperature settings
   • Wait 2-4 hours for recovery
   • Contact service if problem persists
3. Ask for appliance model to look up specific manual if needed
4. Provide relevant technical specs if user asks (capacity, dimensions, power, etc.)

Samsung Refrigerator RF50DG5021 Quick Reference

Models: RF50DG5021CWSC, RF50DG5021EMSC

Temperature Settings:

• Refrigerator: 1~7℃ (default ~3℃)
• Freezer: -23~-15℃ (default -19℃)
• Multi-Zone modes: Freezer (-23~-15℃), Soft Freeze (-3℃), Meat/Fish (-1℃), Fruit/Veg (2℃), Beverage (3℃), Grain/Tea (3℃)

Smart Features: SmartThings app support, Wi-Fi (2.4GHz), Ion Deodorization (model dependent)

Key Questions to Ask User

1. What fault code is displayed?
2. What is the specific problem? (not cooling, too warm, leaking, no power)
3. What is the appliance model number?

Extracting Images from PDF Manuals

Extract all embedded images (diagrams, installation figures):

import pymupdf
import os

pdf_path = "/home/user/hermes-agent/mydocs/knowledgebase/<filename>.pdf"
output_dir = "/home/user/hermes-agent/mydocs/knowledgebase/images"

os.makedirs(output_dir, exist_ok=True)
doc = pymupdf.open(pdf_path)

image_count = 0
for page_num in range(len(doc)):
    page = doc[page_num]
    image_list = page.get_images(full=True)
    
    if image_list:
        print(f"第 {page_num + 1} 页 找到 {len(image_list)} 张图片")
        for img_index, img in enumerate(image_list):
            xref = img[0]
            base_image = doc.extract_image(xref)
            image_bytes = base_image["image"]
            image_ext = base_image["ext"]
            
            filename = f"{output_dir}/<prefix>_p{page_num+1}_img{img_index+1}.{image_ext}"
            with open(filename, "wb") as f:
                f.write(image_bytes)
            image_count += 1

print(f"✅ 总共提取 {image_count} 张图片")

Typical image locations in refrigerator manual:

• Page 1: Product外观图, Logo
• Page 18: 安装尺寸图，空间要求示意图 (8 images)
• Page 21-22: 垫板使用方法，止动块安装图，插座位置图 (26 images)
• Page 33: 控制面板示意图

Creating ASCII Diagrams (when matplotlib Chinese fonts unavailable)

Matplotlib Chinese font issue:

# Will produce warnings like:
# UserWarning: Glyph 20919 (\N{CJK UNIFIED IDEOGRAPH-51B7}) missing from font(s) DejaVu Sans

Fallback: Use ASCII art for structural diagrams:

╔══════════════════════════════════════════════════════════╗
║         三星冰箱 RF50DG5021 内部结构示意图                ║
╠══════════════════════════════════════════════════════════╣
║  ┌────────────────────────────────────────────────────┐  ║
║  │              冷藏室 (325L) 1~7℃                   │  ║
║  │  ┌────────────────────────────────────────────┐    │  ║
║  │  │  ████████████████████████████████████████ │搁板│  ║
║  │  └────────────────────────────────────────────┘    │  ║
║  │  ┌──────────────┐  ┌──────────────┐               │  ║
║  │  │  抽屉        │  │  抽屉        │               │  ║
║  │  └──────────────┘  └──────────────┘               │  ║
║  └────────────────────────────────────────────────────┘  ║
║  ┌────────────────────────────────────────────────────┐  ║
║  │           变温室 (88L) -23℃~3℃                     │  ║
║  └────────────────────────────────────────────────────┘  ║
║  ┌────────────────────────────────────────────────────┐  ║
║  │           冷冻室 (88L) -23℃~-15℃                   │  ║
║  └────────────────────────────────────────────────────┘  ║
╚══════════════════════════════════════════════════════════╝

Important Notes

• Always check knowledge base FIRST - user prefers local documentation before web search
• PDF filenames may NOT match content - verified: "RF8500" filename contains RF50DG5021 refrigerator manual
  • This is a critical lesson: Never trust PDF filenames alone
  • Always extract first 30 pages to verify actual content before referencing
• Use absolute paths for PDF extraction: /home/user/hermes-agent/mydocs/knowledgebase/
• Install pymupdf for PDF text extraction: ~/hermes-agent/venv/bin/python -m pip install pymupdf -q
• Extract systematically: First 30 pages for content ID, then search for keywords, then extract specific sections
• Fault codes are model-specific - verify against correct manual
• Some issues resolve automatically after 2-4 hours if door was left open or hot food was stored
• Normal sounds (clicking, buzzing, hissing, bubbling, cracking) are NOT faults - educate users
• Samsung Customer Service: 400-810-5858 (applicable to all Samsung appliances)
• High humidity condensation (回南天，梅雨季节) on exterior is normal - will disappear automatically
• Images can be extracted from PDFs for diagrams (36 images in refrigerator manual)
• ASCII art fallback when matplotlib lacks Chinese font support
• Knowledge base path: ~/hermes-agent/mydocs/knowledgebase/ (relative to hermes-agent project directory)