If you go inside of a television without knowing what you are doing, you not only have a good chance of receiving an electric shock, but you could kill yourself. That's not hyperbole. A traditional CRT screen needs high voltage, and the circuits inside store those voltages for more then a month after the television is unplugged.
Get it?
No?
Okay; let me put it one more way: this is not meant as an instruction manual on how to repair a TV. This is what I learned from repairing this TV. Its not comprehensive, and its not supposed to be.
If you read this and then open up your television to repair it, you are liable for your own health and well-being from messing around with something that you don't understand. I'm writing this because I know something about televisions but didn't know what to look for to repair mine. Its meant for the people who have a good working knowledge of electronics and know how to safely repair something that stores hundreds of volts.
Please don't open up your Phillips 30PW9100D if you don't know what you're doing. Cool?
On the other hand, if you just wanted to understand what the problem is on this television, go read ahead... and just read.
If you want to add something to my understanding, please leave a comment.
And now my explanation.
I own a nice television. I bought it about two years ago. Its one of the last HD- widescreen televisions that uses a traditional CRT.
For those of you who are interested, until recently, LCD televisions couldn't compare with the color of CRTs. The downside is that CRTs use a lot more power and are really, really heavy. I bought mine as an open-box television, and I got a great deal on it. It has an amazing HD picture. When I first bought it, my cat tried to paw at the birds on the screen.
Unfortunately, the chassis (inside) for my beautiful television was a lemon. Mine is a LO5-1U AA. If you want to know what kind of a chassis your television has, look on the back of the set, near the serial number.
This particular chassis seems to have the same problem that occurs on a lot of sets that were made by this manufacturer at around the same time. The vertical deflection circuit dies after a while, and the screen looks like this:
You might also see a thin white horizontal line. Sorry that these images are fuzzy. (I'm kinda embarrassed about it, since I'm a photographer. I accidentally let the autofocus focus on my reflection in the glass.)
So let me start by answering your first question: why is there a horizontal line if the vertical deflection circuit is the problem?Picture two things that control the beam of light on your screen: a circuit that makes the beam cross the screen horizontally (left to right), and another circuit that deflects the beam vertically (up and down). If the vertical circuit fails, the beam just travels across the screen in a single line... rather then drawing multiple lines.
I found the service manual for the Phillips 30PW9100D and found many references to this problem online. Several people suggested that it was a capacitor. With that in mind, I went hunting for the faulty circuit.
One more time: don't open your television unless you know what you are doing. Don't, don't, don't.
Reminders for those people who do know what they are doing.
- Unplug your television. I actually left mine unplugged for a month before I even went inside.
- Don't touch the anode, or even get near it. If you need to disconnect it, then discharge it. This is the most dangerous thing you could do inside of anything electronic that I know of. Don't play with high electricity unless you know what's going on.
- Don't touch anything on the PCB without knowing that its discharged first. There are some sizable capacitors on the PCB. Don't be fooled into believing that its safe to touch the foil on the backside just because its unplugged.
- Take digital photos of everything before you do it, and make yourself a detailed list of what you did. I put my television back together months after I took it apart. (I had to find the right parts, and wanted to make sure I knew what I was doing.) My photos and detailed list made it easier when I got lost. I even marked off the areas where I unscrewed things, and put red marks on one side of each connector before I unplugged them. It made it easier to orient them.
My television had Torx screws. There were four of them on the outside case, and two that screwed the connection panels to the back of the case. If I hadn't unscrewed these, I would have ripped the connection panels out when I took the case off.
On my television, I had to pull the case straight back. There is a ribbon cable inside of the case that connects to a PCB inside.
Note the empty connector, and the green mark on the one side. Like I said, I marked every connector, and then made a note. I wrapped a piece of electrical tape around each ribbon cable, and wrote stuff on the tape, to make sure I knew where it was meant to go. In this case, the jack has a number that I wrote on the tape.
I took photos through most of the process. When I took off the case, this is what I found:
On the top of my set was the Anode. This contains a lot of voltage. Did I mention not to touch it? Yeah. Don't.
There's a thick wrapped wire that goes around the set. I'm pretty sure this is the degaussing coil, but I don't want to misinform anyone.
On the back of the tube is a small PCB that I've dubbed the CRT board.
From the back, the thing on the left is the Tuner. This is normally the thing that takes the antenna signal and converts it into something that the television can use.
The main board is my target here. Its mounted on a piece of plastic that clicks into the lower case. More on that in a second. I need to point out a few more things:
Here's a different angle, again with the case removed. Note the section that says "a lot of stored up electricity". Anytime that you see really thick wires and a bunch of metal as a heat sink, there is a circuit that contains a lot of electricity.I was super careful anytime I worked around that section.
There are two deflection circuits. One is on a small board that stands vertically on the mainboard. I had to remove it in order to pull the mainboard out. In the photo above, I've already detached the deflection board that I needed to remove. More on that in a minute.
The black box I drew surrounds 3 capacitors. Those are the ones I replaced. I wanted to show you where I found the circuits now, before you see a close up.
Before I could get to any of this, I needed to detach the deflection board that stands up. Its plugged into a blue connector onto the mainboard.
There are tiny clips on the blue connector that hold it to the mainboard. From there, I started to disconnect all of the wires on the deflection board.
Here you can see the five connectors on the deflection board. I labeled each one, and where it plugged in.On the right of this photo you'll see something that says "clip for TDA8177F". That copper- looking piece of metal is a clip. Directly below that is the other half of the same clip that holds the TDA8177F to a heatsink.
Its impossible to explain to you how the clip works, but the vertical deflection IC (TDA8177F) is directly below that clip. I had to push on the top of the clip to get it to let go of the IC.
I had no idea if that IC was the problem... but I decided to replace that too. It only cost me about $3 from the Audio Lab of Georgia. There are a lot of parts to this circuit... but I presumed that the most likely ones causing the problem were the capacitors that I replaced, or this chip.
It was worth it to change all of them.
Finally, here is a photo of the capacitors that I replaced. Note that this whole section is surrounded by heat sinks, and shielding. I know that this section contains high voltages during operation, so I was pretty careful about what I touched even though I had discharged everything.
I had to take the PC board off of the plastic tray to get to the back of the board.
Those 3 blue capacitors were all 470uf, 16v. I replaced them with new ones that had a high tolerance for temperature. I didn't know what the failure was (the vertical deflection IC that I also replaced, or one of these chips) but I wanted to make sure that whatever caused it had less of a chance of happening a second time.
So I de-soldered all 3, pulled them, replaced them (making sure I got the polarity right) and put everything back together.
I check my wiring a few times to make sure I hadn't missed anything, then put the case on loosely. I had a fire extinguisher nearby just in case, and kept my distance from the set as I turned it on.
My first try? I had a good picture, but was missing the sound. I turned it off, unplugged it, and found that I hadn't plugged a cable back in all the way.
I turned it back on and it worked perfectly.
Its uncanny.
I had to change the "format" (from 4:3 back to 16:9), but otherwise, it had kept all of my channels in memory.
I know that these kind of things are generally a result of one bad part. That's what everyone told me. But there's something neat about spending less then $10 on parts (I bought back ups of everything) and having the thing work perfectly. The most expensive thing was the shipping for the parts, which was more then the parts themselves.
Taking the thing apart took me several days. Not because it was hard, or difficult. Just because I wanted to label everything and take my time, and make sure I could put it all back together. I also didn't want to touch the wrong things.
Putting it back together took me less then 30 minutes. I checked off each cable as I reattached it, and still somehow missed pushing one all the way in. Go figure.
I came away from this feeling several things:
- That weird sense of accomplishment that you feel when you do it yourself.
- A vague amazement that I could find the problem on the internet
- A renewed love affair with my TV. Dear God, do I love broadcast HD!
Anyway, I celebrated by watching Almost Famous, the Bootleg edition, at 5 in the morning.
If you have similar problems with this model of television, I'd love to hear your story.
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