Re: RCA L40FHD41 No Power
Update!
Ok, the pin that was showing 1.5v appears to be the power on pin, only thing it could be on that connector by process of elimination. So i jumped a 1k resistor from the 5VSB to that unlabeled pin and BINGO, 24v and 12v outputs are now working and i'm seeing 394v on the primary cap. No noise, no smoke, shes alive!
However... The bad news is when installed in the TV it still won't turn on, so now its a main-board problem.. CRAP...
So i will start tracing out back from the PS-ON pin that i identified and...
kb0nly
Member
Last Activity: 04-28-2018, 12:41 AM
Joined: 10-04-2012
Location: Tyler, MN
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Re: RCA L40FHD41 No Power
On the back of the power supply for the one connector theres a large group of pins labeled 24v, then another large group labeled GND, then a pin labeled BL-ON and DIM, thats the one connector and goes to the backlight inverter board. The other connector that goes to the mainboard has 5VSB, multiple +12v, GND, BL-ON, DIM. There is a few other pins that are unlabeled, i'm assuming one of them is the power on signal, i will have to check each unlabeled pin again, all of them are at 0v except the 5VSB, and another pin that has 1.5v on it.Leave a comment:
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Re: RCA L40FHD41 No Power
Did some more checks, 168v DC after the Rectifier, and the cap is at the same potential, also checked pin 4 of the VIPer22A and its at the same voltage. I saw some other posts that mentioned checking VDD on this IC for voltage and that checked out.
Sooo... Not sure where to go next.Leave a comment:
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Re: RCA L40FHD41 No Power
Now i got manage attachments, apparently it didn't format correctly on my phone, works fine on Chrome on the desktop though....Leave a comment:
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Checked again, there is no manage attachments on advanced? Looked everywhere, even searched the page, not there. Will try a different browser later I guess, must be a formatting issue.Leave a comment:
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Re: RCA L40FHD41 No Power
I just looked on here and even with advanced posting there is no picture upload, so i will have to take pictures, upload them somewhere and link to them, that will take more time.Leave a comment:
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Re: RCA L40FHD41 No Power
I will try and get some pictures of the power supply board tonight, the rest of the TV is packed up to make room on the bench but it's not really much to see since the power supply is the problem.
How do you force these on? The only thing marked is +12v, +24v, 5VSB, and the ground pins on the output side. I don't see any pin labeled as such for turning it on. Usually on the LCD monitor's work on theres a pin labeled EN for enable or PW for power, but not finding it on this thing.Leave a comment:
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RCA L40FHD41 No Power
Got this TV in the other day, was set out by the owner as dead, figured i would take a stab at fixing it since its in nice shape otherwise. Here is what i know and have tried..
Plug in the power cord and the blue LED on the front comes on for about 5-6 seconds then goes off. Will not turn on with the side button or the remote.
Took it apart checked the power supply, there is 5v standby, showing 4.97v there, the 12v and 24v rails are dead, no output, not even a brief showing of voltage when plugging it in or trying to turn it on.
Checked all the caps... -
Re: RCA L32WD22, Power Supply Squeal, Re-Capped
I hope its not the main board. If it is this will likely get stripped down and recycled and tossed, the cost of the board is more then the tv is worth.
I will try replacing the 450v caps first for the heck of it, only cost is about $6 for those, if that doesn't fix it i will salvage what i can and toss the rest.Leave a comment:
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Re: RCA L32WD22, Power Supply Squeal, Re-Capped
Now it won't always turn on.. And when it does turn on it runs for a random amount of time and then goes blank, no video, no sound, but the green power light is still on.
If you wait it will come back all on its own, might take a few minutes, might take ten, but it will come back eventually. Turning it off when it does this makes the problem worse cause then it takes twenty minutes to fight it back on.Leave a comment:
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Re: RCA L32WD22, Power Supply Squeal, Re-Capped
All Nichicon low ESR caps from Digi-Key... As i said its not my first time rebuilding stuff like this, just second guessing what the heck is going on here this tv is driving me nuts.Leave a comment:
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RCA L32WD22, Power Supply Squeal, Re-Capped
I have a 32" RCA TV thats driving me nuts, which is how i found this forum as some searching led me to a few threads here but i didn't really see an answer to my issue.
Its model # L32WD22
Suddenly it started making a loud noise, a high pitched crackling squeal. With my experience i figured time to recap it. I went online and ordered up a batch of caps from Digi-Key, since they are local to me here in MN i use them all the time.
I re-capped the power supply, noise went away and the tv turned back on, awesome! I gave the tv back to a friend of...
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