The screen is very light.I had the main board repaired.It is still very light.I did a firmware update and that added a little bit of color, but the screen is still light.I can read the menu and there is a faint picture
SOURCE: EMERSON EWL2005 20" LCD
Impacting the television can cause the video processor to come unmounted to the main board or the LCD panel inside to become disconnected. You need to take it in for repair.
SOURCE: Philips Magnavox 37" LCD Flat
Disconnect the LVDS Cable that runs from the small signal board to the display panel and apply power,if the screen comes on,the Small signal board (aka Scaler Bd ) is the faulty board. other than that,all that's really left that has gone bad for me is the logic board.
SOURCE: My Toshiba 26HL67 will not
Hello,
The
issue you describe is consistent with a power supply board issue I don't think firmware update will fix this as this is a power problem. Also, how do you intend to update the TV's firmware when it would not power on?
The problem should be from the power board of the TV. This
is the board where the AC goes to. This problem may have occurred as a
result of irregular power supply, or excess power supply or power surge.
The
TV is receiving current but cannot circulate or transfer the current to
other necessary part of the TV because of the defective power supply
board.
I do not think it needs replacement, rather some defective capacitors are causing this issue.
Open
unit up and take a look at the power supply board.You will probably see
one or more electrolytic filter capacitors that are bulged up in the
top-not perfectly flat like the others.
The value of these
capacitors will be different, most likely they will be somewhere
around-820 to 2200uF/25 V( or /10V sometimes)
You can replace
them with same values but I would recommend the voltage rating to be
higher(like 35V for an original 25V) for reliability purposes.
What
happens is,these bulged top capacitors will cause a low and unfiltered
DC voltage=main board will malfunction(the relay will keep clicking
until the caps are holding enough charge to bring the voltage up over a
threshold point).
You can buy these capacitors at any Fry's or
Radioshack store or you can order them online at vendors like
"mcmelectronics.com"(look for electrolytic capacitors).
After replacing these capacitor(capacitors) most likely the normal operation will be restored.
Note:
There may be also some other causes for this symptom ,like a defective T
con board ,or main board,but the bulged top capacitors are the most
common cause for this issue.
If you don't know about TV
repairers, take the TV to the nearest repairman to fix the fault for
you. Also, note that TV stores a lot of current, so wait a while before
opening the TV back cover.
I hope this helps.
SOURCE: I've a LG 32LC56 that
Learn about T-CON board: http://www.scribd.com/doc/25276757/E40951307-TCON-Troubleshooting-10-22-09-OPT PDF download: http://www.mediafire.com/?zzjygannjty
Then:
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 is some troubleshooting 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:
Basic LCD monitor and TV troubleshooting guide:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
http://www.fixya.com/support/r7406380-tv_training_manuals
Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm
Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com
Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps.
Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series.
SOURCE: Does anyone have a main board for the Hyundai PTV421, or a working mcu chip(u3) on the main board?
check rear of tv look for a service socket some have a small plastic cover if you find it you could go to manufacturers site and attempt a software update
59 views
Usually answered in minutes!
×