View Full Version : RCA HD52W56 - buzzing, no picture - fixable?
jfh2112 12-19-2008, 08:53 AM Hi! I found this site by searching for info on this particular TV and found this thread:
http://www.audiokarma.org/forums/showthread.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!
bgadow 12-19-2008, 10:37 PM 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.
jfh2112 12-20-2008, 11:55 AM 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.
rcaman 12-20-2008, 12:49 PM 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
jfh2112 12-20-2008, 03:41 PM 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.
radiotvnut 12-20-2008, 04:01 PM 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.
jfh2112 12-21-2008, 11:26 AM 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?
radiotvnut 12-21-2008, 11:47 AM The wires will not likely disconnect at the flyback itself. They wires will disconnect from wherever they connect to.
jfh2112 12-21-2008, 11:48 AM 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.
radiotvnut 12-21-2008, 12:50 PM You should not need to order the cables. They should come attached to the flyback.
jfh2112 12-22-2008, 02:55 PM 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
radiotvnut 12-22-2008, 03:59 PM 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!
jfh2112 12-24-2008, 02:34 PM 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
rca2000 12-24-2008, 04:40 PM 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.
jfh2112 12-24-2008, 05:51 PM 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?
radiotvnut 12-24-2008, 06:03 PM If it has a suction cup, it sounds like it's for a regular CRT TV. Did you get an original RCA transformer or a generic replacement? I'll let someone else chime in here; but, I suspect you got the wrong part.
rca2000 12-24-2008, 06:44 PM Often times, RCA fly's DO come with the suction cup anode lead on them even if they are for a Projo set. I KNOW the 239111 fly (for the CTC-195 sets) do, as I have replaced MANY of them. For your set--most likely it is the same thing. Just cut the Anode wire long enough to use (making SURE you leave a bit of extra lead, so that it is not "too tight"), and then, cut it off, with the cap. Plug the bare end of this HV lead from the fly into the splitter. Just make sure you got the right part # fly, don't worry about that cup.
jfh2112 12-24-2008, 07:33 PM I double-checked the part #'s and they're the same - I don't know why I have a cap on one lead. <shrug> Oh, well.
So do I need to discharge the old flyback before I go desoldering it? I don't see how, if there's no CRT per se. Someone please tell me before I get zapped! :D
radiotvnut 12-24-2008, 08:12 PM You should be safe. For the record, the HV build up on the CRT will not harm you. It may make you hurt yourself or say a few choice words!
jfh2112 12-24-2008, 10:46 PM I'm not dead! Yay!
Replaced the flyback. Now here's what I get.
Plug in the TV. Red light on logic board. Power button light comes on green, flashes 10 times, goes off. I turn on the TV, it sounds like it's going to power up, but still no picture. I'm guessing - literally - that either I have a bad HV splitter, or my connection from the flyback to the HV splitter is bad. Which is entirely possible, since when I was trying to disconnect the old flyback from the splitter, when I pulled the wire out I just got a stripped end instead of a crimped-on connector. Oops?
I shined some light up in it to see if there was a connector jammed in there, but I didn't see anything - just looks like a small hole. Did I break something?
Oh, and Merry Christmas.
radiotvnut 12-24-2008, 11:05 PM You probably have a bad splitter. The ones I've changed on the CTC169/179 chassis would arc and have lines in the picture if the HV wires were not seated properly in the splitter. And, yes, those wires are a pain to seat correctly. An ex-TV repaiman friend of mine who recently retired from TV repair told me than when they suspected a shorted splitter, he would disconnect the flyback HV lead from the splitter and poke the wire down inside a clean bottle, etc. to prevent it from arcing to something. He would turn the set on and if it powered up, the splitter was shorted. This little trick was good for the older RCA big screens. Maybe someone will chime in and tell us if the same trick is good for this chassis. I don't see why it wouldn't be. If you change the splitter, get an original RCA. Don't buy any of those cheap generic knock-offs. They will turn around and bite you in the butt in short order. I made the mistake of using a knock off splitter in a CTC179 chassis RCA bigscreen that I wanted to sell. It worked for a few months and then that one started arcing just like the original one. I used an RCA original the next time and will never use a generic again. Actually, I probably won't be using any of them again because I've about had my fill of working on big screen TV's. I might feel different if they didn't weigh 9 tons and take up so much room.
jfh2112 12-24-2008, 11:13 PM I can dig that. This thing is huge, and a pain to move around, even with casters. Casters don't help you get it in a truck. :)
I had a look around at the back, and found that R14705 is blown, which leads me back to what I thought was wrong to begin with - bad splitter. Crap. :grumpy:
radiotvnut 12-24-2008, 11:55 PM I wouldn't feel to bad about changing a flyback that may not have been bad. Modern RCA flybacks do not hold up well at all and will die at the drop of a hat. I've seen less than 2 year old RCA's with bad flybacks. OTOH, the flybacks from the '90's and earlier seem to hold up much better, for the most part.
rcaman 12-25-2008, 11:04 AM you didnt read my post very well did you. those flybacks in those sets hold up very well. steve
jfh2112 12-25-2008, 02:11 PM I wouldn't feel to bad about changing a flyback that may not have been bad. Modern RCA flybacks do not hold up well at all and will die at the drop of a hat. I've seen less than 2 year old RCA's with bad flybacks. OTOH, the flybacks from the '90's and earlier seem to hold up much better, for the most part.
It could have been bad. After I replaced the HOT and the flyback, the whine went away, and it sounds like it at least *attempting* to get a picture. And I got better at soldering. :D
The resistor wasn't blown before; I checked all that before I even ordered parts. I should have ordered all of it at once, but oh well. :) It blew after I replaced the HOT & flyback; that's why I think I have a bad splitter also. So now, time to order rcaman's parts list and see what happens.
jfh2112 01-15-2009, 11:22 AM Hi! Remember me? :D
I finally got around to ordering the parts today. Hopefully by next week I'll be able to post pics of a working TV!
Even if it doesn't work, thank all of you for your help. I really appreciate it.
jfh2112 01-23-2009, 11:05 PM OK, so no pics of a working TV. :(
However, I *do* get a picture now! :thmbsp: I almost woke everyone up with my triumphant hollering when I powered on the TV after installing the HV splitter and the new resistor and saw "Unusable Signal" on the screen. Here's what I've got now:
Hooked the XBox 360 to the TV with the HDTV cable, using component connections (no HDMI on my 360). TV powers on like it should. I still have a red light on the logic board. The picture is stable in the middle, but towards the edges you can see horizontal lines flickering across the entire width of the picture. In the corners is especially bad; there's some image "tearing". The flickering occurs even if there is no video source. The picture also appears somewhat "washed out", like the whites are too white, the blacks aren't black enough, and everything else is kind of "meh". :no:
I'd take a picture, but I'm not sure it'd come out; I can try if anyone wants to try to get a look at it.
EDIT: Got some pictures and an update.
http://www.flickr.com/photos/34685865@N04/3223166502/
I ran the TV for about an hour this morning getting pictures, and suddenly the lines just went away. I immediately became suspicious and unplugged the TV, because I'm pretty sure it's about to go out again. ;) I pulled out the module on the left side and tore it down and gave it a look, but nothing jumps out at me as far as anything wrong. I put it all back together & plugged it in to confirm I still have a red status light. :headscrat
rcaman 01-24-2009, 02:07 PM looks like you did not insert the highvoltage wire into the splitter good enough. as far as the blurry pix. clean the lenses and mirror. steve
jfh2112 01-24-2009, 03:26 PM looks like you did not insert the highvoltage wire into the splitter good enough. as far as the blurry pix. clean the lenses and mirror. steve
You were right - I restripped the HV wire and reconnected it to the splitter. I still get the red light on the 'logic' board* when I connect power. <part about lockups redacted - turns out it was the 360 and not the TV that was locking up :(>
BTW, I cleaned the lenses & the mirror - holy crap. Major improvement in picture quality. Thanks for that tip.
Where can I find a service manual for this beast?
*That board actually contains the cable & antenna tuners and the CableCARD slot. I just don't know what else to call it, since I don't have a svc manual or anything.
jfh2112 01-28-2009, 08:24 PM 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
OK, so like a cheapskate idiot, I didn't order replacements for R14718 and R14719. I really should have listened to you. <kicking self>
R14718 is reading 30K, and R14719 (a 30K, ironically) is reading 6.5K.
On the plus side, I know now how to read resistor bands. Of course, that doesn't make the TV work... :drool:
Tritronics doesn't have the 30K resistors in stock; they're listed as NLA. Where's another good parts source? Mouser has *tons* of resistors, but I'm not sure about exactly what to get. Any advice?
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