FANUC A61L-0001-0093 Display Abnormality Troubleshooting

1. Overview of A61L-0001-0093

The FANUC A61L-0001-0093 is a 10.4-inch CRT display originally equipped with FANUC 0i, 16i, and 18i series CNC systems. Manufactured in the 1990s-2000s, these displays are now reaching the end of their service life.

Specification	Original CRT	LCD Upgrade (Kongto)
Display Size	10.4 inch CRT	10.4 inch LCD
Resolution	640×480 (VGA)	1024×768 (XGA)
Signal Interface	HONDA 20-pin	HONDA 20-pin (compatible)
Power Supply	24V DC	24V DC (compatible)
Power Consumption	60-80W	15-20W
Lifespan	10-15 years	15-20+ years
Warm-up Time	2-5 minutes	Instant-on

2. Common Faults

Fault Type	Symptoms	Possible Causes
No Display	Screen completely black, no power	Power supply failure, fuse blown, mainboard damage
Dim Display	Image barely visible, very dark	CRT aging, filament failure, high-voltage failure
Distorted Image	Colors incorrect, ghosting, flickering	CRT electron gun aging, signal cable damage
Horizontal/Vertical Lines	Fixed lines on screen	CRT deflection coil failure, driver board issues
Frequent Shut-down	Display turns off intermittently	Overheating protection, component failure

3. Diagnostic Steps

Step 1: Visual Inspection

• Check power indicator LED (should be green or orange)
• Inspect HONDA 20-pin connector for loose or damaged pins
• Look for physical damage (cracks, burns, swelling capacitors)
• Smell for burnt components

Step 2: Power Supply Test

• Measure input voltage at HONDA connector pin 1&2 (should be 24V DC 卤10%)
• Check fuse continuity (located on power board)
• Test power supply output with multimeter
• Verify grounding connection

Step 3: Signal Test

• Check HONDA 20-pin connector pinout (reference FANUC manual)
• Measure signal voltage levels (RGB: 0.7V p-p, Sync: TTL level)
• Test with known good signal source if possible
• Verify horizontal/vertical sync signals

Step 4: CRT Specific Tests

• Check CRT filament continuity (should be 0.5-2惟)
• Measure high-voltage output (should be 15-25kV)
• Listen for high-pitched whine (indicates high-voltage section working)
• Check for flicker (indicates CRT aging)

4. Power Supply Issues

4.1 Fuse Blown

Symptoms: No power indicator, completely dead display

Solution:

1. Disconnect power and discharge capacitors (wait 5+ minutes)
2. Locate and remove blown fuse (usually 2A/250V slow-blow)
3. Check for short circuits before replacing (prevents immediate re-blow)
4. Install new fuse and test

4.2 Power Board Failure

Symptoms: Fuse intact but no power output

Solution: Replace power board or repair damaged components (capacitors, transistors, diodes). Note: CRT high-voltage section is dangerous! Leave to qualified technicians.

5. Signal Problems

5.1 Loose or Damaged HONDA 20-pin Connector

Symptoms: Intermittent display, flickering, "No Signal" message

Solution:

1. Power off CNC system
2. Re-seat HONDA 20-pin connector (ensure all pins engaged)
3. Inspect cable for broken wires or damaged pins
4. Replace cable if damaged
5. Apply contact cleaner to connector pins

5.2 EMI Interference

Symptoms: Ghosting, distorted image, random flickering

Solution:

1. Check grounding of display and CNC system (resistance < 1惟)
2. Add ferrite cores to signal cables
3. Re-route signal cables away from power lines (min 30cm separation)
4. Install EMI filters if necessary

6. CRT Failure Symptoms

6.1 CRT Aging (Most Common)

Symptoms: Dim display, takes 5+ minutes to warm up, flickering, colors shifted

Causes:

• CRT filament aging (emission capability decreased)
• Phosphor layer aging (brightness reduced by 50%+)
• Electron gun aging (focus deterioration)

Solution: CRT replacement is not economical. Recommended to upgrade to LCD. LCD upgrade kit costs ~CNY 2,500-3,500, while CRT replacement part is rare and expensive (if available at all).

6.2 High-Voltage Section Failure

Symptoms: No high-voltage output, screen completely dark, no filament glow

Solution: Dangerous to repair! High-voltage section operates at 15-25kV. Recommend replacing entire display or upgrading to LCD.

7. Repair vs Upgrade

Option	Pros	Cons	Cost	Recommended?
Component-Level Repair	Lowest cost	Requires skilled technician, time-consuming, unreliable	~CNY 200-500	鉂?No (temporary fix)
Board Replacement	Faster than component repair	Hard to find parts, may need adjustment	~CNY 800-1500	鉂?No (parts scarce)
CRT Replacement	Keeps original appearance	CRT parts obsolete, very expensive if available	~CNY 3000-5000	鉂?No (not recommended)
LCD Upgrade Kit	Modern technology, long lifespan, improved image, plug-and-play	Higher initial cost	~CNY 2500-3500	鉁?Yes (recommended)

8. LCD Upgrade Benefits

• Plug-and-Play: Direct replacement using original HONDA 20-pin connector, no wiring modification
• Improved Image: 1024×768 resolution vs 640×480 (CRT), clearer text and graphics
• Energy Efficient: 15-20W vs 60-80W (CRT), 70%+ energy savings
• Instant-On: No warm-up time, display appears immediately
• Long Lifespan: 15-20+ years vs 10-15 years (CRT)
• No Flicker: Stable image, reduces eye strain for operators
• Thin and Light: LCD panel only 3-5 kg vs 8-12 kg (CRT)
• Wide Temperature: -20°C to +70°C operating range

9. When to Upgrade (Decision Flowchart)

1. Is the display 10+ years old? →?Yes: Upgrade recommended
2. Is the image dim or flickering? →?Yes: Upgrade recommended
3. Have you repaired it 2+ times in past year? →?Yes: Upgrade recommended
4. Are replacement parts unavailable or expensive? →?Yes: Upgrade recommended
5. Is production downtime costly? →?Yes: Upgrade recommended (LCD is more reliable)

Kongto Technology A61L-0001-0093 LCD Upgrade Kit Includes:

• 10.4" Industrial LCD Panel (1024×768)
• LCD Controller Board (HONDA 20-pin compatible)
• Mounting Bracket (matches original CRT mounting holes)
• Installation Manual
• 18-Month Warranty

For professional LCD upgrade solutions and technical consultation, contact Kongto Technology:

• Email: [email protected]
• Phone: +86 13686889647
• Website: https://cncdisplay.com/