Don't dump your CRT RPTV! - Page 213

Just getting ready to give a good ole' 57 RPCRT a face lift. Mr. (Master) Bob is performing the procedure.

CRT technology is still the defacto technology, until something commercially available comes along... CRT is it.

Stay tune for the calibration tune up update. It should be interesting and convincing that CRT technology is the one to beat.

Bob is at your place right now? What the hell? He should be on here answering questions...for free.

Just starting...

Side by side ... mine sucks!!!

OMG... fixing a tiny speed bump became a whole structure redo....

Looking real good, will post pictures later.

I'm faced with a humanitarian project, a Pioneer SD-P5181-K SD 51" RPTV that is really acting up. This particular TV was one, and still is, one of the brightest RPTV's I've ever seen - and it has the matte screen that completely kills window and sunshine glare. But it is SD and I should shove it off my porch or gut it and make it a nice equipment rack since it has the full cabinet with the wonderful flat top that you can stack 200 lbs of components on (!).

But I like to fix stuff - no, I like to see them come back to life. Almost a compulsion but not quite. This set could give someone a lot of satisfaction if I can repair it for $nil. And it would cause me to start shopping for a used RPHDTV which is my real ulterior motive.

First apologies may be in order since I'm not really sure if this the appropriate thread/forum for such a post. I know others have talked about rather detailed repairs and when replacing IC's on a PCB, that is about as hardcore as it gets so maybe I'm not too far off base. Also, being a SD set, I didn't find any explicit HD in the titles of this thread/section so maybe I'm not too far off topic I hope.

So let me get started with my

PROBLEMS:

1) First, it started as convergence jumping in and out. The first thing I did was start hitting the TV to see if it was a mechanical problem. Well, it seemed to be. Eventually, I opened the front up and probed the boards with a wooden stick. Found sensitivity in the power supply board away from the big components, near smaller ones in the front.

I'm thinking bad solder joints.

2) Decided to resolder the convergence board in the vicinity of power circuitry - not the area of the IC's. Well this got rid of the instability but the convergence was off.

3) Got into the factory mode and found that when trying to adjust, I would get point where further correction produced zero effect - the convergence voltage was clipping at some level. So I think there is a problem with supply voltage. A lot of people say the convergence chip is also a common culprit. So I set things as best I could and left things go at that.
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Some months pass.

4) While the above condition has existed, CRT output is getting weird:

focus is off
brights are still bright
lows are completely black
menus are dim and blue (color balance of lows is off)
convergence is so dim it is unsettable
setting contrast the last bit to max produces a massive increase in brightness
when graphics are overlaid on a picture, the brightness changes

5) I decided to resolder the remaining portion of the convergence board. The result is weird in that when I try to step through the convergence points, there appears to be no red step anymore. However, the graphics are so dim, it may be the red gun at that low level is has no output.
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At first I thought it was a convergence problem, either bad solder or perhaps a low voltage being supplied by power supply.

Now with the guns all out of wack, the high voltage section is now suspect.

I know that some TV's get their voltages from the flyback transformer which is really crappy and I don't know if that is the case with this TV. I did read a post from 2007 for this very model that a fellow found the flyback transformer solder joints were MASSIVELY bad. He resoldered them and got a dramatic correction and problem solved.

Any thoughts?

Usually a single problem is the cause and with all these problems, if a single cause, it should be easier to find. However, these problems have evolved over a period of a year or two so it could be multiple problems.

Bad Solder Joints is the only thing I know for a fact since resoldering the convergence board did completely eliminate the convergence jumping in and out problem.

More Resoldering, I suppose, is mandatory for any attempt at a fix. Since it was a serious problem in one PCB, it is probably systemic.

Any help would be greatly appreciated,
Thanks in advance,
Tom

PS. I do have the service manual.

I dumped my CRT RPTV! It was a Mits WS-65869. Gave it away free on CL. The guy who picked it up could not fit it into his pick up truck because he had a cab on it. He ended up putting the top half of the tv inside his truck cab, and put the bottom half (containing mirrors and guns) onto the top of his truck cab. Then he covered it up with a bunch of blankets I gave him. It took him over 2 hours to get the monster onto his truck. He left happy.

Thanks for the advice. Resoldering is almost always worth a shot in my book. My big problem now, is that I've procrastinated so much, I can't remember if I resoldered the main power supply board since I found mechanical sensitivity in it. Those interior boards are such contortionistic pieces.

But I must say I'm really excited to hear about your observation of "a halo around its leg on the pad." I did a search and found you further discussing it at http://www.avsforum.com/avs-vb/showt...=402397&page=7

Appears the "halo" is the fracture line which can appear white-ish.

I will say this, I have inspected memory connectors on laptop motherboards which are notorious for cracking and rendering that slot unusable. Using nice stereo microscopy, I can agree with you completely that these cracks are invisible, however, all you have to do as far as memory slots go, is just put the least amount of pressure on them with your finger/probe while watching and out of nowhere, you will see the crack open and close. To really inspect a joint, I use magnification that makes the solder glob about 25-50% of my field of view. And as expected, the max stress point are the outer most solder points. Maybe the last 3 legs will have cracks on each end of the memory slot. It is so dramatic to see that crack open, I should take a video of it and put on youtube but I don't have the time.

Thanks for the expert advice.

I'm thinking the very first thing to do is survey my voltages at the various connectors, then proceed with the resoldering. However, the more I think about it, the more I think I've already resoldered the main power supply board which if true, is bad because that means I have a problem with a component. If it is the flyback transformer, its probably game over. Maybe I'll get lucky and it will be some electrolytic caps.

Tom

Sure my 1080i picture looks great but it doesn't fit.

Some more shots of after calibration ... Went to bed, got up and found out Bob has been working all night!!!

Some shots from this morning.

BARAKA reference material.

I was thinking flyback because lots of sets use flybacks for, like you said, several AC voltages. And it sounds like I definitely have some low voltage problems and probably high voltage as well. The flyback would sure be a candidate if it has low V coming out of it too.

I did find the Tripler but I didn't locate the flyback yet. Looking at the power supply schematic it is depressing not to see some big power transformer with all the taps! Of course, if that transformer fails, it is usually Good Night Irene since they are all one-of-a-kind designs. (Of course, you could rig something close since you are only looking for a particular AC voltage. But that has nothing to do with ...)

I need to suck it up and crawl in there and get some voltages. (Actually, it would be nice to have the TV elevated bench high. Ha Ha Ha Dream on...)

Found the flyback in the schematic. It has the obvious High Voltage taps, but it also has the +-25v rails which power the convergence board and also the High Tension (+-HT) Regulator.

Sounds like all the trouble areas converge there.

On the parts list and schematic it is an ATK1064 while on the component/trace view of schematic it is an ATK1063.

Did a few internet searches and found prices around $100 for it. Actually, methodically cruising eBay might be a good tactic too.

That's all for now,
Tom

Mr Bob -

Wow, very nice work, easy to see the improvement even in the still shots. It looks like the after shots are more zoomed in than the before shots though, you can see where there are areas of picture present in the 'before' that aren't in the 'after', is there a reason for that?

Other than that, are you going to be in South Florida anytime soon?

Hey guys,

I have a Sony 65WV700. I have had this since 2003 and it has been a great TV.

Recently though, it has developed these parallel bowing horizontal lines that are visible only when the screen is black, or dark. As with no video input, or a very dark scene.

I looked in the CRT lenses and the lines can be seen in each. Close viewing of the screen shows they are the combo of red, green and blue, producing a faint white.

The closeness and bowing of the lines changes as I change the mode. Where HDTV full screen has only slight bowing and the parallel lines close together. Zoom mode also shows two extremely bowed and brighter lines on top and bottom. These bow in, kinda like two half moons, top and bottom. This is the only mode that shows these lines bowing inward top and bottom. In the other modes, the only lines are side by side, bowing upward.

I'm wondering if anyone knows what this could be? If it would be something easy to fix?

Any info would be great...Thanks!

Thanks,

The picture geometry is fine, the lines are just there in the background and only are visible when the screen is dark. Picture quality is also fine. It is the Zoom mode that has the more prominent lines top and bottom, even cuts through normally lighted scenes...but never use that mode anyway.

P.S. I did lose geometry over a year ago. I had ex warranty thankfully and the tech replaced the units that hold that together. Can't remember what they are called, but have big heat sinks as I recall.

In a way, the lines almost look like those generated for doing adjustments in the service menu. But, they are not exactly like any convergence patterns I have done when I was in the service menu years ago.

Have a Sony KDP-65XBR2. Has a convergence problem. The shop changed the convergence board, but that didn't fix the problem. Pushing the flash focus will align the colors, but after a little bit, the colors drift. The other inputs convergence are off, and I have to flash focus them with the same result. All the guns were changed over the years. Any suggestions? Cold joints, bad convergence board IC's, power board? Thanks.

I made a decision. I bought a plasma tv Samsung PN63B590 to replace my Hitachi 57SWX20B rptv. I just have to have the latest innovations e.g. hdmi connections, 1080p, 24 fps, etc. I am keeping the Hitachi and put it upstairs. It will be an effort to move since the beast is 265 lbs heavy.

So I am heading to the plasma forum. Bye guys.

Bye bye.

I just ordered a new Samsung PN50B650 to replace my Sony KP-46WT510 which is only six years old. But after reading some of this thread, I'm wondering if the Sony might be worth fixing.

It worked perfectly until about a month ago. When I turned it on, the RGB images were separated by a good three inches and the geometry was bowed inward from all four sides for each of the color guns. Powered off, back on and it was fine for another week. The the same thing again followed by another week OK, now permanently screwed.

Anybody familiar with this syndrome?