Vfd Is Not Displayed When Power On The Set - LG CJ65 Service Manual

3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET

When power on the set, any icons or characters on VFD are not displayed.
3-1. VFD
3-1-1. Solution
Please check and replace VFD300 on FRONT board.
3-1-2. How to troubleshoot (Countermeasure)
1) Check if 12 VA is output from SMPS to VFD via the MAIN board.
2) Check if Check if LED_5 V, DVCC_3 V output from the MAIN board.
3) Check if IC500 outputs VFD_D0, VFD_CLK and VFD_STB to the FRONT board.
4) Check if VFD300 output SW signal to the FRONT board.
  If the SW signal isn't output, replace VFD300 with new one.
5) check if Q300 and Q301 to the FRONT board.
  If the VH signal isn't output, replace Q300, Q301 with new one.
  If the VH signal is output, replace VFD300 with new one.
3-1-3. Service hint (Any picture / Remark)
ONE POINT REPAIR GUIDE
< Waveform of GR and SG signal >
3-5