RCA HD52W56 - buzzing, no picture - fixable?
 

Hi! I found this site by searching for info on this particular TV and found this thread:

http://www.audiokarma.org/forums/sho...d.php?t=135653

which is incredibly informative, so I thought I'd ask about my TV.

It's exactly the same model and chassis # as the one in the referenced thread (RCA HD52W56, chassis ATC321), but my problem is slightly different. This was also a curbside TV; the guy told me this was the second time it's gone out and he just decided to replace it with an LCD TV instead of repairing it again.

When I got it home & turned it on, the light on the power switch would light green, then flash 11 times, then turn off. I found a reset code for the TV and did that; now the light comes on and stays on, but there's a buzzing sound coming from the bottom left. I popped the back off of it and the buzzing seems to be coming from what I'm guessing is the flyback - I don't work on TVs or monitors, so I'm not terribly familiar with the terminology (I'm a computer guy). There's also a red light coming from the logic board. The cooling fan spins up, and I can hear popping when I change inputs, so I think the logic may be OK, although that red light bothers me. I don't have a service manual, so I'm not sure if that's just a standby light, or if it means there's something wrong with the board.

I'm thinking, from what I've read about this TV, that I may be able to replace the flyback, maybe the HV splitter and the three problem resistors referenced in the other thread, and have a nice 52" HDTV. Am I on the right track, or is this TV not fixable?

I can post pictures later today if needed, but I'm at work right now.

Thanks in advance for your help!

Others should come along soon with better help but I will say, most problems are either bad solder joints or bad capacitors. I would spend a little time hunting around for the former, especially around the flyback. Might need a small magnifying glass to help you find a hairline crack. Good luck! Sounds like a worthy project.

If that's all it is, I'm going to be ecstatic! I've never had a big TV before - or an HD TV. I'm going to pull the board later today and go over the traces & see what I can find, then report back.

Do I need to worry about high voltage? It's been disconnected from mains since Wednesday afternoon.

R14718 is a 120k @ 1/4 W, part # 260880. R14719 is part # 175046, no value given. R14705 is part # 238958, a 27K 1/2 W. Splitter is 258512


you will need all these to get it back up and running splitter is under the picture tubes in the middle. order your parts from tritronics.
r14705 is a 30k ohm resistor. good luck steve

Update:

Pulled the board & looked for cracks, blown resistors, etc. Nothing. I did find where it blew the first time - R14705. I tested all the resistors, and they seem OK, but I'm not a TV guy, so they're getting replaced.

Put the board back in and pulled the front speaker grille - found the HV splitter. Checked the connections were secure.

Got my son's ClickStart TV game and hooked it to the composite inputs. Turned on the TV - high-pitched whine from near the flyback, red LED on logic board. Cycled through the inputs until I found composite - I get sound!

rcaman, should I go ahead & order the parts you listed? R14719 isn't available, but appears to test OK.

I'm not familiar with this model; but, check the horizontal output transistor for shorts. It should be a large transistor mounted on a heatsink close to the flyback. On the direct view sets; the HOT will short and cause the power supply to whine. Often, the HOT shorts due to a defective flyback.

I think we have a winner!

The HOT appears to be blown through. I'm ordering the HOT and a flyback from Tritronics.

How hard is it to replace the flyback? The wires coming off the top appear to be sealed on, but that can't be the case, can it? Just really hard to disconnect?

The wires will not likely disconnect at the flyback itself. They wires will disconnect from wherever they connect to.

Will I have to order those cables separately, or do they normally come with the flyback? They don't have a picture of it at Tritronics, so I can't tell.

You should not need to order the cables. They should come attached to the flyback.

OK, placed an order today with Tritronics for an HOT and a flyback. Parts should be here for Xmas Eve; hopefully I'll be getting a working 52" HDTV for Xmas. Will post pics of either the TV working or me in a rage. :D

Don't do what I do and lose your temper and sling the thing. That's what I usually do and then, when it's too late, I realize that I probably could have fixed the thing!

Parts received today - but just barely! UPS Air freight was late landing today; didn't get my 2nd Day freight until this afternoon.

Do I need to discharge the flyback? The TV has been unplugged since Saturday. I'd really like to know before I start sticking soldering irons to it! :D

Ok--I will try and guide you here....

The wires WILL remove from the splitter. BUT--they are difficult to remove!!

What you will need to do, is to get enough wire length to rotate EACH of the anode wires on the splitter, CCW, while pulling on them. IT WILL take some trial and error, but they WILL come out. I KNOW this -I have replaced a few of them, as I work on the new stuff daily.

Then, AFTER you replace the splitter AND the burnt resistors, HOPEFULLY the HV will come up. If so--you are probably done.

And NO you should NOT need to discharge the HV--I am SURE it is a low Z to ground with the bad splitter anyway--so no worry there.

OK, problem. :(

The replacement flyback I have has a suction-cup style connector on one of the leads. The one in the TV has the two twist-type leads. I can post pics if need be. Did I get the wrong part?