Hello everyone,
Attempting my first TV repair and looking for a few pointers.
I know this is a older unit, but I figure if I can fix it with a few dollars in parts then Ill give it a go before junking it.
I have a good working knowledge of electrical systems, and a background in automotive electrical systems, so Im familiar with DVOMs and such.
I did some searching on this site, and came across a few posts with similar tvs/problems.
https://www.badcaps.net/forum/showthread.php?t=9982
https://www.badcaps.net/forum/showthread.php?t=19601
and a few others helped me get started.
First the symptoms: TV worked fine for years, and one day went to turn it on and no go. Standby LED flashes green for a few seconds, back-lights flash and then it goes back to red.
Took tv apart and looked around a bit for any bad caps, etc. Didn't see anything that looked burnt. Unplugged the ribbon cable on board that has the back-light transformers and tried to power on the TV. Led flashes and goes steady green, but of course no picture since the board is unplugged.
In my mind that tells me that the fault lies somewhere on that board.
I unplug all the back-light transformers from the lights (2 pin connectors) and plug them in one at a time, powering on the tv between each one to see if it lights up its respective light.
Each one lights up except number 3. I took the #3 light harness and plugged it into the #2 transformer and got a light flicker when I tried to power it up.
In my mind, this tells me the transformer, not the bulb is bad on number 3. I suppose the fault could be anywhere in the circuit before the transformer as well...
I found the website that sells replacement transformers and for 8 bucks was willing to take the gamble...but before I pulled the trigger I figured I could play around a bit more.
I desoldered the transformer and removed it from the board. With it removed I hooked everything back up and attempted to power on the TV.
This is where my TV repair confusion comes in. In my mind, if the short was in the transformer itself, and I removed it from the board, the TV should operate as normal with one back-light not lit up. Is this correct?
I tried my theory and the TV still flashes quick, the led blinks green, and then goes back to red.
What im trying to figure out is this:
Will removing the assumed transformer from the board allow the tv to operate with one back-light not lit -OR- is the TV still going to go into a protection mode until a new transformer is installed?
Any suggestions on what else I should try or check next?
Thanks!
Joe
Attempting my first TV repair and looking for a few pointers.
I know this is a older unit, but I figure if I can fix it with a few dollars in parts then Ill give it a go before junking it.
I have a good working knowledge of electrical systems, and a background in automotive electrical systems, so Im familiar with DVOMs and such.
I did some searching on this site, and came across a few posts with similar tvs/problems.
https://www.badcaps.net/forum/showthread.php?t=9982
https://www.badcaps.net/forum/showthread.php?t=19601
and a few others helped me get started.
First the symptoms: TV worked fine for years, and one day went to turn it on and no go. Standby LED flashes green for a few seconds, back-lights flash and then it goes back to red.
Took tv apart and looked around a bit for any bad caps, etc. Didn't see anything that looked burnt. Unplugged the ribbon cable on board that has the back-light transformers and tried to power on the TV. Led flashes and goes steady green, but of course no picture since the board is unplugged.
In my mind that tells me that the fault lies somewhere on that board.
I unplug all the back-light transformers from the lights (2 pin connectors) and plug them in one at a time, powering on the tv between each one to see if it lights up its respective light.
Each one lights up except number 3. I took the #3 light harness and plugged it into the #2 transformer and got a light flicker when I tried to power it up.
In my mind, this tells me the transformer, not the bulb is bad on number 3. I suppose the fault could be anywhere in the circuit before the transformer as well...
I found the website that sells replacement transformers and for 8 bucks was willing to take the gamble...but before I pulled the trigger I figured I could play around a bit more.
I desoldered the transformer and removed it from the board. With it removed I hooked everything back up and attempted to power on the TV.
This is where my TV repair confusion comes in. In my mind, if the short was in the transformer itself, and I removed it from the board, the TV should operate as normal with one back-light not lit up. Is this correct?
I tried my theory and the TV still flashes quick, the led blinks green, and then goes back to red.
What im trying to figure out is this:
Will removing the assumed transformer from the board allow the tv to operate with one back-light not lit -OR- is the TV still going to go into a protection mode until a new transformer is installed?
Any suggestions on what else I should try or check next?
Thanks!
Joe
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