-Part Type AU Board AU Mount PC Board Signal Board -Part Number A-1184-344-A MFR Part Number 1 A-1184-344-A -Board Number(s) A-1204-353-A 1-871-231-11 -Known Models KDL-40V2500 KDL-46V2500 KDL-46V25L1 -Panel Sticker Number LTY400HS-LH3 We are here to help! If you're unsure of how to diagnose and troubleshoot the TV message or call us for more assistance before purchasing! We offer FREE PROFESSIONAL TECH SUPPORT. The only real way to properly troubleshoot / diagnose is by trial and error since there could be several boards that show similar symptoms and possibly more than 1 board not working. Sometimes the symptoms change. Be patient with questions from us and exchanges! For help with first timers go on YouTube and search "TV Repair Tutorial" *NOTE* LG & Vizio TVs must be plugged in for 5 minutes before it will turn on* *For main board replacements check firmware upgrades online - We can not pre-install them* 1. Inspect ALL Ribbons and connectors. Any tears or bad connections between boards must be replaced FIRST 2. If you have any of these boards, it should be the first board to be replaced A) T-Con Board - Video Problems (No Video with standby light on, audio but no video, grainy, distorted, or color problems in screen) B) X or Y Buffer Board (Plasma TVs only) - Standby light is on but no power C) Backlight Inverter / LED Driver - No Video with standby light on 3. Main Video Board - Standby light is on but no power - Either video or audio does not work (if no T-Con in TV. If audio but no video it is T-Con) 4. Power Board - No power AND standby light does NOT turn on. If standby light is on try other boards above 5. Panel - No power, distorted picture, lines, slow motion, half screen, faded in / out. Panel problems are usually not worth replacing the panel.