Author Topic: Fixed our TV (sort of)  (Read 1887 times)

Gone Fishing

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Fixed our TV (sort of)
« on: June 15, 2015, 09:32:27 AM »
So our 5-6 year old Dynex LCD TV suddenly stopped working a month or two ago.  The power light would come on, but no image would show.  I didn't really want to buy a new one, and really didn't want to take a chance on a Craigslist/pawn find either (the ones I found were only running $30-40 less in our smaller size).  So we have been watching Prime and DVD's on the laptop.  I was given an ultimatum by the SO for replacement (kids are home for summer), so I watched a few youtube videos, and on Saturday, popped the back off.  Nothing appeared burned up, so I checked every connection I could find.  Nothing appeared loose, and I figured I couldn't hurt it too much more so I gave it the ol' technical tap, and presto, the screen stared displaying again!  But it was not to last, upon reassembly, the picture failed again.  Several disassemblies and reassembly's later and while things seem to be working I am still not confident that the loose connection has been identified as operation is still intermitant, and I have to remove the back to readminister the proper technical tap that restores function (but once it is on it seems to stay on).  So for now, it is kind of like that old car that requires you to hold your face just right, push here, and pull there, but it works!

zolotiyeruki

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Re: Fixed our TV (sort of)
« Reply #1 on: June 17, 2015, 10:02:07 AM »
You might check the capacitors on the circuit boards.  I've fixed a lot of LCDs that have failed caps--the tops are bulging or ruptured.  Pretty easy fix, if you know what you're doing.

guitar_stitch

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Re: Fixed our TV (sort of)
« Reply #2 on: June 17, 2015, 11:50:39 AM »
If a tap brings it back, you likely have a cracked solder joint on the board.  Where?  Who knows.  You may need a magnifying glass to find it.  Once you do, all you'll need is a 20-30w solder pen and maybe a dab of fresh 60/40 rosin core solder to correct it.

Most components can be touched while the unit is on.  I won't recommend that, however, because I don't want you to accidentally find the LCD fluorescent power supply circuit.  If you are brave, you can wiggle components (usually larger components) until you find one that affects the picture display.

Gone Fishing

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Re: Fixed our TV (sort of)
« Reply #3 on: June 17, 2015, 12:23:40 PM »
No capacitors are bulged (don't think banging on the TV would make a broken cap come back to life) and I did poke around with a non-conductive tool with the power on trying to find the loose spot, but no luck.  TV was still working last night, though!