Brand:
LG
Category: Monitor
Document Type: Parts/Service
Language: EN
Parts/Service for 27UL600
Uploaded: Nov. 21, 2025, 7:45 p.m.
This service manual provides detailed information for servicing the LG LED Monitor, model 27UL600. It includes safety precautions, general guidance for servicing, specifications, signal timing details for DisplayPort and HDMI, a block diagram, exploded views, assembly/disassembly instructions, and troubleshooting guides for common issues such as no power, no screen on, no video via HDMI or DP, no USB-C functionality, and no sound. The manual is intended for qualified service personnel.
Troubleshooting and error codes
| Problem | Check Point | Action |
|---|---|---|
| 1. NO POWER | JP400, JP401 Voltage Level (19V) | Y: Check Power connector OK? N: Replace Adapter |
| IC601 Output Voltage Level (+3.3V) | Y: Check IC405, IC403, IC404 Output Voltage Level (5V, 1.8V, 1.15V) N: Replace IC601 & Recheck | |
| IC405, IC403, IC404 Output Voltage Level (5V, 1.8V, 1.15V) | Y: Check X200 Clock 12MHz N: Replace IC405, IC403, IC404 & Recheck | |
| X200 Clock 12MHz | Y: Replace IC202 Flash Memory N: Replace X200 | |
| 2. NO SCREEN ON | Module Back Light On? | Y: Check Panel Power (10V/JP209) N: Check WLED_ENABLE High? (IC601 Pin #27) |
| Panel Power (10V/JP209) | Y: Check e-DP Cable for Damage or Open Conductors N: Replace IC402 & Recheck | |
| WLED_ENABLE High? (IC601 Pin #27) | Y: Replace T-Con Board or Module N: Check IC 601 Replace Main Scaler IC | |
| 3. No Video-HDMI | Check signal format and resolution Is it supported? | Y: Check HDMI Cable for Damage or Open Connector N: Replace Connector |
| HDMI Cable for Damage or Open Connector | Y: Check JK100 or JK101 for proper connection or Damage N: Re Download EDID Data | |
| JK100 or JK101 for proper connection or Damage | Y: Check HDMI 5V from Source(PC) (JK100 and JK101) (Pin No. 18) N: | |
| HDMI 5V from Source(PC) (JK100 and JK101) (Pin No. 18) | Y: Replace Main Scaler (IC200) | |
| 4. No Video-DP | Check signal format and resolution Is it supported? | Y: Check DP Cable for Damage or Open Connector N: Replace Connector |
| DP Cable for Damage or Open Connector | Y: Check JK801 for proper connection or Damage N: | |
| JK801 for proper connection or Damage | Y: Check AUX Signal (R137 or R142) N: | |
| AUX Signal (R137 or R142) | Y: Replace Main Scaler (IC200) | |
| 4. No USB-C | Check input signal format Is it supported? | Y: Check USB-CCable for Damage or Open Connector N: Replace Connector |
| USB-CCable for Damage or Open Connector | Y: Check JK801 for proper connection or Damage N: ReplaceIC801 | |
| JK801 for proper connection or Damage | Y: Check AUX Signal (R876 or R890) N: | |
| AUX Signal (R876 or R890) | Y: Replace Main Scaler (IC200) | |
| 5. No Sound(H/P) | Check the Input source. | Y: Check Cable status for Damaged or Open Connector N: Setting like a right image. |
| Cable status for Damaged or Open Connector | Y: Check the sound setting in PC N: Do re-soldering | |
| Sound setting in PC | Y: Check JK501 Soldering N: | |
| JK501 Soldering | Y: Replace Main Scaler (IC200) | |
| 6. No Sound(Speaker) | Check the Input source. | Y: Check Cable for Damaged or Open Connector N: Connect the Cable correctly |
| Cable for Damaged or Open Connector | Y: Check Speaker Cable is connected N: Replace Main Scaler (IC200) | |
| Speaker Cable is connected | Y: Replace Speaker and Check the status N: |