Bad 24vdc power supply, T-CON board, backlight inverter board.<br /> <a name="OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">First, look at the screen in darkened room to see if you can see any slight glow from the screen, if it does, then the problem can be the T-CON (not getting the 12vdc) or the main logic board not feeding the signals to the T-CON board. </span></a><br /> <span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">if not, next place to check will be the power supply module, make sure it has 24vdc which is required by the backlight inverter to work, the reason for not having 24vdc can be from bad DC filter caps (leaking/bulging top, high ESR) or short circuits in the inverter board which will cause the 24vdc supply to go into shutdown mode, so you may have to disconnect the power cable that feed the inverter board to see if the 24vdc will work without the inverter board hookup, you will need to apply about 3~4 amp of load to the 24vdc to make sure it can handle that. There are fuses on the backlight inverter boards also. So there are some troubleshoot you will have to do to find out the causes of the problem you are having.</span></span><br /> <span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'"> </span></span><br /> <span style="mso-bookmark: OLE_LINK1"><b><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on:</span></b></span><br /> <span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'"> </span></span><br /> <span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Please see my basic troubleshooting guide here:</span></span><br /> <span style="mso-bookmark: OLE_LINK1"></span><a rel='nofollow' href="http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide"><span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide</span></span><span style="mso-bookmark: OLE_LINK1"></span></a><span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'"></span></span><br /> <span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'"> </span></span><br /> <span style="mso-bookmark: OLE_LINK1"></span><a rel='nofollow' href="http://s807.photobucket.com/home/budm/allalbums"><span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt">http://s807.photobucket.com/home/budm/allalbums</span></span><span style="mso-bookmark: OLE_LINK1"></span></a><span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt"></span></span><br /> <span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt"> </span></span><br /> <span style="mso-bookmark: OLE_LINK1"></span><a rel='nofollow' href="http://en.wikipedia.org/wiki/Capacitor_plague"><span style="mso-bookmark: OLE_LINK1"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">http://en.wikipedia.org/wiki/Capacitor_plague</span></span><span style="mso-bookmark: OLE_LINK1"></span></a><span style="mso-bookmark: OLE_LINK1"></span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'"></span><br /> <span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt"> </span><br /> <span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt">Parts: <a rel='nofollow' href="http://www.shopjimmy.com/">www.shopjimmy.com</a></span><br /> <span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Capacitors kit: <a rel='nofollow' href="http://lcdalternatives.auctivacommerce.com/Viewsonic-C196320.aspx"><span style="mso-spacerun: yes"> </span>http://lcdalternatives.auctivacommerce.com/Default.aspx</a></span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt"></span><br />
SOURCE: I have a LG 42LC6DF
Either failed 24vdc power supply or shorted out backlight inverter board, but try unplugging it for an hour to let it reset itself first.
First, look at the screen in darkened room to see if you can see any slight glow from the screen, if it does, then the problem can be the T-CON (not getting the 12vdc) or the main logic board not feeding the signals to the T-CON board.
if not, next place to check will be the power supply module, make sure it has 24vdc which is required by the backlight inverter to work, the reason for not having 24vdc can be from bad DC filter caps (leaking/bulging top, high ESR) or short circuits in the inverter board which will cause the 24vdc supply to go into shutdown mode, so you may have to disconnect the power cable that feed the inverter board to see if the 24vdc will work without the inverter board hookup, you will need to apply about 3~4 amp of load to the 24vdc to make sure it can handle that. There are fuses on the backlight inverter boards also. So there are some troubleshoot you will have to do to find out the causes of the problem you are having.
If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on:
Please see my basic troubleshooting guide here:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://s807.photobucket.com/home/budm/allalbums
http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com
Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx
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