Fixing My Own TV, Part I

Read Part II Here!

Sunday morning, the convergence on our 47" Panasonic HDTV (model: PT-47W53G) went haywire. The green gun's image had a big bow in the bottom up about 8" and the upper right corner was stretched off screen, giving everything a weird set of green and magenta shadows. I was pretty sure it was a hardware problem, but I went ahead and made sure the problem occurred on all modes (standard definition and HDTV modes) and all inputs (cable, DVD, etc.). I knew that it was too far off to fix with the onscreen convergence menu and besides, the green channel is the fixed reference - you can only adjust the red and blue to converge on the green. I did go into the service menu to see if I could do a manual convergence enough to watch while I waited to get it fixed, but the green didn't respond at all.



Next, I started Googling. It took a while to wade through reviews and casual mentions of my model and to try to get the right search terms, but the general consensus I found was that the convergence amplifier chip had gone bad and that I could expect to pay around $400 to get it fixed. I called a recommended local repair shop here in Huntsville (American Video Services - they came highly recommended by several people, so I'll give them a plug) and that was about the quote I got, plus $100 for them to pick up the TV, fix it, return it to my house, and re-adjust it.

Now I had a dilemma. The TV cost around $1300 when I bought it three years ago and now, for the same price, I can get a bigger one with better features and go for an LCD or DLP instead of a CRT projection. But I didn't want a new TV for Christmas and it would blow the rest of our Christmas budget. Even if I had bought the extended warranty on the TV it would have expired by now. One annoying thing I found is that Panasonic and Hitachi sets that use this particular chip have a very high failure rate for it after about three years of use. It was so common that when I found the right sites, it was a common question - "Help! My red|green|blue convergence just went bad! What do I do?" followed by several replies of "Replace your convergence amp ICs." So, I am about 95% sure that is what is wrong with it.

Did I want to pay 1/3 to 1/2 the price of a new TV to fix this one?

Most of the replies on the tech boards I found followed the advice with, "You can replace them yourself if you know what you are doing." Hmm. Do I know what I'm doing? I've tinkered with electronics all of my life - building electronic kits, putting together computers, hacking weird projects, and opening up or tinkering with settings on just about every piece of electronics that I own. I can use a soldering iron and a multimeter. But I'm a long way from being an expert and I've never tried to fix something so expensive. You have to remove the rear of the TV, avoid the high voltage electronics, pry the chips off their heat sinks, unsolder the chips (over 32 pins), mount the new ICs on the heat sinks using heat sink compound, then solder in the chips. It isn't just a tweak a few trim pots or plug in a new board or module type fix.

I read and re-read the boards (which I'll list at the bottom of this post - they are great resources) and then decided I would try it. I found the part (an STK392-110, Panasonic part number C5AA00000108) based on links from some of the posts at an online shop called www.partstore.com for $29.08. The cool thing about this shop is that you can enter the make and model of your TV and it will list hundreds of parts specific to your model - tuners, amps, even replacement cabinet parts. Only one IC is bad, but the posts recommend replacing both. I was about to order them when I decided to search a bit more. I found another post saying that they got theirs for around $6 apiece from www.electronix.com and successfully repaired their Hitachi TV with them. Bingo - I checked their site and found the same parts (I hope) for $5.99 apiece. I ordered two with 2 day shipping for under $30. With the Thanksgiving holiday this week, I hope I'll them by Friday, but it may be Monday or later. I'll post part II when I get them.

Wish me luck!

In the meanwhile, we're using Renee's video projector from school and a neat freestanding projector screen that I found at a thrift store for $6 to watch TV in the living room. Strangely enough, we have three computers, four video game consoles, probably eight or nine DVD players (if you count the ones in the computers and game consoles), but we only have two TVs - the big one that's broke and the TV tuner in our desktop computer. The other TV is hooked up to the game consoles and doesn't even have cable ran to it.



Here are the cool repair/tech advice websites that I found. These should be useful if you have questions about TVs and other consumer electronic devices, even if you aren't going to fix them yourself.


TechLore - The Consumer Electronics Community

FixYa - Technical Support, User Guides and Repair Service - this is where I got the best advice

HDTV Voice - High Definition Television Talk

Read Part II Here!