View Full Version : Advice on (hopefully) simple repair to RCA HDTV


YamahaFreak
11-21-2007, 11:52 PM
Yep, I've done it again! Second curbside TV in a month. :D This one is a 2004 RCA (Thompson:grumpy:) 52" HD rear projector. The guy said it quit working about a week ago. I get it home(inquire about sidesplitting story!:D)and plug it in. The standby LED lights up and the power supply energizes, but the set doesn't turn on. I remove the back panel and find a thoroughly toasted resistor on the back of the mainboard, well away from the PSU. The carnage on the board roasted off most of the part #, but judging by the others on the board, I think it is number R14703. The rest of the board is clean. Pics:

http://img210.imageshack.us/img210/5631/1020790nr3.jpg

http://img411.imageshack.us/img411/1545/1020791du9.jpg

http://img211.imageshack.us/img211/7751/1020792wj4.jpg

Also, in the first pic, you can see on the screen what looks like shadowy arches; I don't know if this is a burn or other damage to the screen, or just a reflection. It's only noticeable from some angles under certain lighting. Hoping to get this working to go in our pool room for Super Bowl and gaming. :thmbsp:

radiotvnut
11-22-2007, 12:27 AM
Have you got a model or chassis number. Should be on a piece of paper located on the rear cover. I'm not familiar with RCA's newer bigscreens; but, their direct view sets of this era are known for having bad flyback's. You'll probably have to obtain service information on this set to determine what value the resistor is. Then, you'll have to find out what drew too much current and burned the resistor. You may try tracing the foil on the underside of the board to see what the resistor connects to. You may possibly have some type of solid state device (IC, transistor, diode, etc.) that has shorted. And, it could have very well have been the flyback that went bad. Like I said, they are high failure parts in the direct view sets.

YamahaFreak
11-22-2007, 12:36 AM
The model number is HD52W56, chassis #ATC321. There is no mention of DirectView anywhere on the set. Where would I obtain said service info?

andy
11-22-2007, 12:55 AM
That's a carbon composition resistor, so it's probably a very high value resistor (1M or 10M). The only places they often still use these are for things like coupling the line to the chassis.

YamahaFreak
11-22-2007, 01:01 AM
That's a carbon composition resistor, so it's probably a very high value resistor (1M or 10M). The only places they often still use these are for things like coupling the line to the chassis.

Meaning? (sorry, :stupid:) Also, like with the last set I was working on, could I replace this resistor without touching anything else? I will remove the board and look at the traces when I get back from Thanksgiving vacation on Saturday. :yes:

radiotvnut
11-22-2007, 01:23 AM
I looked on the internet and found that he HV splitter is a very common problem on these sets and can burn some resistors with it. R14705, R14718, & R14719 are said to be the resistor location numbers of the ones that smoke. The HV splitter part number is 258512.

YamahaFreak
11-22-2007, 01:39 AM
I looked on the internet and found that he HV splitter is a very common problem on these sets and can burn some resistors with it. R14705, R14718, & R14719 are said to be the resistor location numbers of the ones that smoke. The HV splitter part number is 258512.

I scraped off some of the burn with my fingernail and the blown resistor is indeed R14705. :yes: Still new at this; what is a HV (assuming stands for High Voltage) splitter and what does it look like? Also, where on the chassis is it usually located, and are they expensive/hard to replace? Sorry for all the questions.

EDIT: I just perused the PS and mainboard for ten minutes and couldn't find anything with #258512 on it.

Bill R
11-22-2007, 10:03 AM
The splitter is usually located off the main board. It is a small box with 4 or 5 large wires connected to it. It splits the high voltage from the flyback to each of te 3 projection tubes. They are not usually to hard to replace.

Bill R

radiotvnut
11-22-2007, 11:06 AM
That RCA part number is usually never on the parts. The only way you can get the RCA part number is to either have the service information or some type of parts cross reference for the set. I just happened to find the part number on the internet. If you replace the splitter, try to stick with an original RCA. It's been my experience that the cheaper generic ones don't hold up that long.

NowhereMan 1966
11-22-2007, 01:10 PM
Yep, I've done it again! Second curbside TV in a month. :D This one is a 2004 RCA (Thompson:grumpy:) 52" HD rear projector. The guy said it quit working about a week ago. I get it home(inquire about sidesplitting story!:D)and plug it in. The standby LED lights up and the power supply energizes, but the set doesn't turn on. I remove the back panel and find a thoroughly toasted resistor on the back of the mainboard, well away from the PSU. The carnage on the board roasted off most of the part #, but judging by the others on the board, I think it is number R14703. The rest of the board is clean. Pics:

http://img210.imageshack.us/img210/5631/1020790nr3.jpg

http://img411.imageshack.us/img411/1545/1020791du9.jpg

http://img211.imageshack.us/img211/7751/1020792wj4.jpg

Also, in the first pic, you can see on the screen what looks like shadowy arches; I don't know if this is a burn or other damage to the screen, or just a reflection. It's only noticeable from some angles under certain lighting. Hoping to get this working to go in our pool room for Super Bowl and gaming. :thmbsp:

Dang, that looks like the same set my buddy just bought at Wal*Mart this week (his F-150 is down so I helped him take it home in my Ford "Exploder") so that's why I'm keeping my eye on this thread to see if there is any more issues.

rcaman
11-22-2007, 01:53 PM
you will have to replace the splitter or watch those parts go up in smoke again. those are great playing sets. about $50.00 bucks in parts and you have a fine tv. steve

rcaman
11-22-2007, 02:01 PM
ok here are your part numbers. splitter 258512 r14705 238958 which i believe is a 27k ohm 1/4watt carbon r14718 260880 r14719 175046 tritronics has the splitter and resistor in stock. that is where we buy all our rca parts. they are original not generic.

YamahaFreak
11-24-2007, 03:41 PM
Thanks for the help, guys! I'll get on this repair ASAP. Does anyone have a link to the Tritronics site? I Googled it and all I see is dog training sites? :confused: :D

radiotvnut
11-24-2007, 03:44 PM
www.tritronicsinc.com

YamahaFreak
11-25-2007, 03:55 AM
I did some more snooping and found this component behind the front access panel beneath the speaker grille. Would this be the HV Divider?

http://img402.imageshack.us/img402/7218/rcahvdividerun0.jpg

Looks kinda like a mutated flyback, with each of the three leads going to one of the three RGB CRTs. The fourth lead is coming from the main flyback, I assume? Also, when replacing, do I disconnect the leads at the tubes or the divider? :scratch2:

andy
11-25-2007, 01:11 PM
That would be it. You disconnect the wires from the divider because they are glued to the CRTs. Usually, you push and twist the wires a half turn to unlock them.

There's a lot of cigarette tar in that set. Be sure to clean the lenses, mirror, and inside of the screen if you want a good picture!

YamahaFreak
11-25-2007, 01:32 PM
That would be it. You disconnect the wires from the divider because they are glued to the CRTs. Usually, you push and twist the wires a half turn to unlock them.

There's a lot of cigarette tar in that set. Be sure to clean the lenses, mirror, and inside of the screen if you want a good picture!

Yes, definitely. :yes:

EDIT: The splitter itself was easy to remove (1 screw) but I'm having trouble removing the leads on top. The rubber boots around the wires are just pulling off. I don't want to push something too hard, for fear of crapping something up. :scratch2: Let me go try again.

Here's a photo of the splitter with the wire boots pulled up. I can't really tell how the wires are attached to the unit. :dunno:

http://img152.imageshack.us/img152/613/rcahvdivider2qc7.jpg

rcaman
11-25-2007, 08:06 PM
hi again, youre gonna have to put some grunt into removing those wires. just jet you a pair of pliers and yank them out. there not like most that you have to push in and turn to remove. and when you install the new splitter you can feel when the wire seats back in the new splitter. steve

YamahaFreak
11-25-2007, 08:09 PM
hi again, youre gonna have to put some grunt into removing those wires. just jet you a pair of pliers and yank them out. there not like most that you have to push in and turn to remove. and when you install the new splitter you can feel when the wire seats back in the new splitter. steve

So, will I see a bare wire end, or a connector, or what? And I can just push the leads into the new splitter and that's it? Sounds easier than I expected! :banana:
EDIT: I was able to remove the splitter.:yes: The bare cable ends look like needles. I marked each lead with a Sharpie so I wouldn't mix them up, just in case.

Also, is it this resistor

http://www.tritronicsinc.com/storefrontB2CWEB/itemdetail.do?action=prepare_detail&itm_id=392679&itm_index=5

and which of these three choices should I go with?

http://www.tritronicsinc.com/storefrontB2CWEB/itemdetail.do?action=prepare_detail&itm_id=109168&itm_index=0
http://www.tritronicsinc.com/storefrontB2CWEB/itemdetail.do?action=prepare_detail&itm_id=109623&itm_index=1
http://www.tritronicsinc.com/storefrontB2CWEB/itemdetail.do?action=prepare_detail&itm_id=331073&itm_index=2

Also also, after I was told to look for R14718 and 719 to be bad, I looked and found 718 blown. 719 looks good still, I'll check it with the trusty DMM.:yes:
EDIT: R14719 is still intact. Oddly, 718 reads as still closed, but because it's burnt. I'm replacing it anyway. It sure as heck is a good thing 719 is good, because Tritronics discontinued them! :yikes:

YamahaFreak
11-26-2007, 08:38 PM
I'm going to go ahead and purchase one of their not in box original RCA dividers and the two resistors. :yes: If there is a reason I should go with the NIB one, let me know.

rcaman
11-26-2007, 08:49 PM
it will come back to bite you in the butt. dont buy a generic splitter. that thing has 30000 volts comming and going out of it. the cheap ones wont hold up as long. steve

YamahaFreak
11-26-2007, 10:07 PM
it will come back to bite you in the butt. dont buy a generic splitter. that thing has 30000 volts comming and going out of it. the cheap ones wont hold up as long. steve

So this one would be better:

http://www.tritronicsinc.com/storefrontB2CWEB/itemdetail.do?action=prepare_detail&itm_id=109168&itm_index=0

YamahaFreak
11-27-2007, 08:47 PM
I went with the original RCA divider ($50.85). Odd, the website asked me for a 'PO Number', which I don't know what is, so I just put N/A and it worked.

For me, the hardest part of this repair will be removing the old resistors and soldering in the new ones. I've never soldered onto a board before. :withstpd:

YamahaFreak
12-03-2007, 03:24 PM
OK, the parts got here today. (all correct) I installed the new HV block no problem, but I've never done any small-scale soldering, so I'll need some tips on putting in the new resistors. (and removing the old ones) Also, I need to actually dig out my iron. :D Will I have to remove the board from the set to get at the bottom of it for any reason? Another big question is, if I turn on the set after replacing only the HV divider, will I fudge something up?

freakaftr8
12-03-2007, 04:32 PM
Basically the way I do it is go ahead and grab one lead with needle nose pliers, have the board in the air to where you can access the solder point. Apply the soldering iron onto the area between the point and the flat area on the solder area. you will see the solder start to turn shiny. at this point the part you are pulling on will pop off the board. Installing the new part you want to set the post of the new resistor into the hole of the board. hold the iron on the solder area and the part will start to slide through the board. Do this on both ends, make sure there are no voids in the area where the post of the new resistor and the solder on the board meet or you will have to apply a sittle solder. Once you achieve this, ude some wire cutters and clip the excess from the bottom of the board. Basically look at the other components installed on the board and make this job you just completed look like the solder that was done to those and dont let the excess post hang lower than those. This should help you.. (Note: Do not hold the iron on the board for more than it takes to melt the solder or you will burn through the board!!)

YamahaFreak
12-03-2007, 04:54 PM
Basically the way I do it is go ahead and grab one lead with needle nose pliers, have the board in the air to where you can access the solder point. Apply the soldering iron onto the area between the point and the flat area on the solder area. you will see the solder start to turn shiny. at this point the part you are pulling on will pop off the board. Installing the new part you want to set the post of the new resistor into the hole of the board. hold the iron on the solder area and the part will start to slide through the board. Do this on both ends, make sure there are no voids in the area where the post of the new resistor and the solder on the board meet or you will have to apply a sittle solder. Once you achieve this, ude some wire cutters and clip the excess from the bottom of the board. Basically look at the other components installed on the board and make this job you just completed look like the solder that was done to those and dont let the excess post hang lower than those. This should help you.. (Note: Do not hold the iron on the board for more than it takes to melt the solder or you will burn through the board!!)
Thanks for the tips. Also, does the polarity of the resistors matter? I wasn't sure, so I thought I'd ask first just to be safe. :yes:

freakaftr8
12-03-2007, 05:10 PM
No. On resistors, polarity does not matter... When this set comes up and running, post pics!

YamahaFreak
12-03-2007, 05:13 PM
No. On resistors, polarity does not matter... When this set comes up and running, post pics!

Will do:thmbsp:

YamahaFreak
12-03-2007, 07:09 PM
I've got all the parts in, and I still have no high voltage. I can't hear the whine or see the heaters in the CRTs light up. I DO have sound, because when I adjust the volume, I can hear the little 'clicks' as the volume increases. The relay in the set also stays on; before it would click once and then click again half a second later. The set seems to stay 'on' i.e. the relay doesn't click again until I press the power button. I'm thinking I made a wrong connection somewhere? :scratch2:

EDIT: A green LED can now be seen on part of a board inside the set while it's plugged in.

radiotvnut
12-03-2007, 07:10 PM
You could also buy some desoldering braid from Radio Shack or other electronics store to remove the resistors. Just place the braid on the solder you want to remove and place a hot iron on the braid. You'll see the molten solder soak up into the braid.

YamahaFreak
12-03-2007, 07:26 PM
I checked inside again, and it seems I left a cable disconnected. I reconnected it, replaced the back panel, and...


:yippy: It works!!! :D Pic:

http://img527.imageshack.us/img527/4070/workingbigscreenwithmarsq7.jpg

I want to thank everyone who posted in this thread for helping me bring this set back to life. It took all this to finally bring an HDTV (or big-screen of any kind, for that matter) into our house, and I couldn't be happier. :huge:

sampson159
12-03-2007, 09:55 PM
i would love to see that set,but it comes up forbidden. why ya shutting me out?
as always,i m outside looking in.

radiotvnut
12-03-2007, 10:01 PM
I'm glad you were able to get it going. It's always nice to be able to make something good out of someone else's trash. It amazes me how much good stuff people throw away that can easily be made to work. They'd rather spend big $$ on something new than bother with trying to fix it. Every TV I've ever owned was either a trash find, a donation from the TV shop, or a donation from an individual. Of course, I'm real happy that people would rather replace than repair because it keeps us supplied with plenty of good stuff.

radiotvnut
12-03-2007, 10:02 PM
I just got the same forbidden message.

YamahaFreak
12-03-2007, 10:15 PM
Photo link fixed. :D

freakaftr8
12-04-2007, 04:40 PM
Awsome! Glad to see it working! Congrats to a tv fix well done...

sampson159
12-04-2007, 04:50 PM
LOOKS BEAUTIFUL! i am happy with your success. these techs in this forum are the nicest,friendliest, folks you will ever have the pleasure to know. they have helped me and i am forever indebted. well done!

jaspars7
01-26-2009, 06:14 PM
I've got the same problem on my RCA Scenium. It just went out and when I push the power button, I hear the fan kick on, power button lights up and then it shuts off. I turn on power again and it does the same thing. I took the back of the TV off and found the exact same restrictor burnt to a crisp. Assuming that I have the same problem, I followed the advice given and replaced the HV Splitter which was smooth sailing and then I replaced the restrictor by connecting it to the two on the right side of the board as instructed. After installing the new parts, I crossed my fingers and hit the power button and, no luck. Still doing the same thing it was at the start. I'm gonna take a few pics and post them up so you guys can see what I've done. In the meantime, any ideas? In the back of the TV, on the right, at the bottom, inside the bottom box, I can see a red light that comes inside when I plug it in and the fan starts up, but after a few seconds, it shuts off and then tries to start back up about 3 times before it just shuts off.

YamahaFreak
01-28-2009, 12:47 AM
I've got the same problem on my RCA Scenium. It just went out and when I push the power button, I hear the fan kick on, power button lights up and then it shuts off. I turn on power again and it does the same thing. I took the back of the TV off and found the exact same restrictor burnt to a crisp. Assuming that I have the same problem, I followed the advice given and replaced the HV Splitter which was smooth sailing and then I replaced the restrictor by connecting it to the two on the right side of the board as instructed. After installing the new parts, I crossed my fingers and hit the power button and, no luck. Still doing the same thing it was at the start. I'm gonna take a few pics and post them up so you guys can see what I've done. In the meantime, any ideas? In the back of the TV, on the right, at the bottom, inside the bottom box, I can see a red light that comes inside when I plug it in and the fan starts up, but after a few seconds, it shuts off and then tries to start back up about 3 times before it just shuts off.

How many resistors did you replace? IIRC, I replaced a total of three in mine, one fat carbon-core one and two smaller striped ones. Make sure that all the connections on the HV splitter are secure-I had to push them in pretty hard. FWIW, my set is still going strong...:music: