TV repair anyone?

[Roundabout]

gmatov, You're absolutely right. Normal solder = 60% lead/40% tin (as I recall) and he can get it at R/S for next to nothing. A 40w Soldering Iron is only 4 or 5 bucks. Now you're getting close, Hatz! I hope you'll be able to see it. What George said is correct, you might be able to see it "spark" if it's dark enough in the area where the connection is broken. Since it probably is a connection with a fair amount of current going through it (vertical output transistor, or related component). When you pull it out, the closer you can get to the area where you think the broken connection is, you can do what Village Idiot suggested, resolder everything in that area, if you can't see which connection is broken. You'll have to melt some small amount of new solder on each connection to be sure it takes. Don't just heat up old solder. You must use fresh solder to make it right. Don't use too much, but melt a small amount on each connection and make sure you don't short two connections together. A magnifying glass is very helpful, especially if connections are close together. Have you soldered before? Helps if you have a little experience with it. Keep us informed what happens!

[The village idiot]

MAKE SURE YOU UNPLUG THE POWER BEFORE SOLDERING!!!!!!!!!! Otherwise, sparks will fly Let it sit for a few minutes before you start to solder, that way the capacitors can discharge a little before you start grounding them with the iron. I would suggest a slightly lower wattage iron. SOmething in the 25 to 30 watt range. Most of my work I use a 15 watt iron. But anything bigger than a component lead will take a hotter iron.

[gmatov]

Village,

I wouldn't argue with you, for the sake of safety. The lad has brushed his arm across some apparently hot leads/points, whatever you wanna call them. I still don't know what they were. The only time I got anything like that, it was just a hole burnt into a finger, no ZAP to it.

There are not that many hi-pot points on a board.

Ah, well

[Hatz]

Hey there. I just want to say thank you to everyone for all of your help. You have really helped me narrow it down. Here is where I am at now. I think I have located the spot like I said before. I took some pics to show you the bottom of the board and the top.

What kind of soldering points do I need to look for exactly or should I just solder every point in that general area?

1st pic is the top of the board. Notice where it says V. Height and V Line.........I'm guessing that might mean Verticle Height and Verticle Line.....which is my problem. I get horizontal line but no verticle.



At this point my toothbrush located anywhere from the number 1,2, to 3. In that general area.


The second pic is the bottom of the board......sorry its so blurry but it gives you a general location of where I am at. The straight line of points located at #1 is that metal looking heatsink thing on top of the board next to the baby blue capacitors........to the bottom of that around area 2 and 3 is where the toothbrush is at again.




So I guess I am asking........should I just solder all these small points and then see if it works from there or should I look at a diff part of the board.

Thanks everyone. I appreciate it greatly.

Hatz

[The village idiot]

Picture no linky



Tweak the V Height potentiometer. Mark the pot with a sharpie, and then just give it a small twist. Make sure you put it back to the same spot that it started. DO the same with the V LIN pot if that doesn't work. After that, take a solder iron and heat every joint in that area.

[The village idiot]

Is it just me or does C70 (C70x) look like it is burned? It is to the left of the #3 and slightly lower.

[gmatov]

Just to advise you, it's Vertical Linearity.

[The village idiot]

Just to advise you, it's Vertical Linearity.

Thanks, I was too lazy to spell it.

[Roundabout]

Hey guys,

Lots of good advice...but first of all, I will mention that the Cap C70 is not burned, it has a black dot on top that indicates temperature tolerance (if I remember correctly). Good eyes, though, Village!
Hatz, I would start with soldering the output IC that is on the heatsink, they run hot and it's possible that it has a broken solder joint on the lead coming through the board. That's a starting point. In general, try the larger components, especially ones that generate heat, such as Heat sinked Transistors, Power Resistors (such as the pink one at the top of the picture close to C521 and D556), and voltage regulator IC's. I can't tell for sure from your picture, but it looks like the heat sink goes further to the right, with possibly more components attached to it?
Try to use a magnifying glass, if you have one, and move each lead individually (with the power off) and see if any move at all. By grabbing them with tweezers, you can "wiggle" them a little and see if they appear to move around inside the solder. They should be solid, bending at the base where they are soldered, not moving the slightest. When you get your iron, just start soldering everything in that general area that is a larger component. Although smaller caps and resistors can break connection too, usually it's a larger component. You can even move the component on the top side while looking at the leads of it on the bottom (again with the power off) as another method. Sure, it's hard to find sometimes, but odds are, all that is wrong is a broken joint. You just need to isolate it and resolder it. Fun...

[gmatov]

Village,

That wasn't for your benefit, but for Hatz. He's the one trying to learn, and thought it was line.

Hey, anything I know that he wants to learn is his.

The curious is one thing, the stubborn is another.

Cheers,

George

[Hatz]

And I thank you all. I am going to work on it tomorrow I think for a bit......its kinda hard to have any free time when I spend all of my nights studying for tests. I have a total of 4 tests this week. That puts my free time to nothing......ah well.....2 down and 2 to go. Better get back to the books. THANKS AGAIN TO EVERYONE.

Oh and by the way........Roundabout was right about that point that looked burnt. It is just brown in color with a black dot on top. Very good eye though. I had to take a third look at it....hehehe

Hatz

[The village idiot]

Village,

That wasn't for your benefit, but for Hatz. He's the one trying to learn, and thought it was line.

Hey, anything I know that he wants to learn is his.

The curious is one thing, the stubborn is another.

Cheers,

George

What about the curiously stubborn,or the stubbornly curious.

And your were right about the disks. I thought it sounded funny too, but now I proved it! Me thinks it's time for some refunds!

And Hatz, you got PM. Good luck on the tests! :P

[gmatov]

Village,

Maybe I shouldn't answer this here, but stubbornly curious/curiously stubborn, I'll help.
Hatz is one, Shocker is another, they wish to learn, and they both seem to be. Hey, how many guys are gonna rip a TV apart to try to find a cold joint? You can buy a 20 inch Apex for 100 even + tax. Now there is stubbornly curious. "I can do this!" The only way we can keep any mechanical/technical knowledge in this country. And as for you, I liked the way you did the shimming, filing, whatnot to get the printer to feed 5 times the thickness the engineers designed it for. And straight thru feed, on a machine that curves the paper, or the HP that reverses the direction totally, 180 curve, few disks would have done that, maybe an 8 inch, didn't know them, whether they had a solid hub like a floppy has.

It's some others who just want to go to war.

You are not in that category. I don't know your age, but you seem to have a good head on your shoulders.

Love this site. Lots of smart pipple here.

Cheers,

George

[waynezo]

I am having a problem with my toshiba 55" cinema series tp55h95 rear projection tv. it is 5yrs 2mos old and the extended warranty just ran out.
The convergence keeps going out of whack. I re adjust it but it doesn't stay. it is the red color on the plus sign that is out of alignment and it is worse toward the edges. please advice me as to what kind of repair it needs, what it should cost, and if i can do it myself.
Any advice will be greatly appreciated.

[Roundabout]

Question: When do you do the convergence, when the unit is first turned on, or after it's warmed up? The reason I ask, is because as the projection tubes age, like any picture tube, they get weaker and tend to have a "blooming" effect as they warm up. If you adjust it when it's cold, then it changes convergence later after it's warm, it is probably a CRT problem (or if you adjust it when it's warm, then when it's cold, it won't be converged properly). Projection CRT's are driven harder, run hotter and don't last as long as regular CRT's, and if the TV is used a lot, they will wear out faster than a normal TV. You could try to change the CRT yourself, however, it's not something I would recommend unless you have some experience with electronics. Also, they aren't cheap. You best bet is to sell the TV if you can, while it still looks acceptable. The price of large screen TV's have come down a lot on the rear-projection models, in some cases below $1000, where it probably wouldn't be cost effective to spend a lot in repairs on an older model.

[waynezo]

I adjusted the convergence after the set warmed up and so far it seems to be holding. Now I am noticing the color to be a little washed out and with a brown tint. could this also be a sign the CRT's are about to go?

[Roundabout]

"About to go" is a relative term in this case, because they don't just die, they get worse as they age, like any CRT. If the color has changed over time and you haven't changed any other settings, then you're probably seeing the aging of the tubes. However, if you noticed a sudden change in color it would be more indicative of an electronic component problem.
I don't know how many user-accessible settings are on your set, some have more than others. Of course, you can increase the color intensity (level) to compensate for washed out color, but it's not going to look as it should, or like when the set was newer. A good test is to look at a black & white signal, you should see a natural looking B&W picture, it shouldn't look like it has a brown or reddish tint to it (or greenish or bluish). It's possible to compensate by adjusting the "screen" or "drive" controls internally to make the B&W (and therefore the color balance) more natural, but as the tubes continue to age, it will lose tracking and have to be adjusted again. You can improve it temporarily and it might be OK for a while. However, unless you're comfortable working inside a running TV with high voltages, you might not want to attempt it, you have to think about that. It would help if you have a service manual for your model to see exactly where the settings are and it would probably tell you exactly what the procedure is. It would be difficult for me to tell you where inside your set to look as they are all different. If you get a manual and need help, let me know.