View Full Version : Just fixed my first plasma TV.
radiotvnut 01-29-2010, 02:08 PM Some guy brought me a 42" 5 year old Hitachi plasma TV that was given to him by his father-in-law with the complaint of a blown speaker and a ripped off RF connector. Once I removed the 10,000 screws holding it together, I removed the analog tuner module. Once I removed the shielding from the module, I was able to slide the RF connector back on to the edge of the PC board and resolder it. Once I put the shielding back on, I soldered the connector on to the shield to give it a little extra security. Every time I replace the RF connector on a TV, I always solder it in place.
Only one speaker was blown; but, I replaced both of them so the sound would be equal. What I used was slightly different than the originals.
Stuck it all back together and the owner was happy.
Maybe my luck will start changing on these flat panel TV's as I've had several come my way; but, I was unable to fix any of them. My friend that has a shop says he fixes many LCD sets by changing bad caps; but, I wasn't that lucky on the ones that I got. Most of the ones that I got had already been written off by other shops, anyway. I'd like to find some broken FP sets to play with; but, most people want $100+ even for the broken ones and I'm not willing to gamble that much money on something to play with. Years ago, when I was buying broken CRT sets to play with, I never gave over $10 for a broken TV. As far as I'm concerned, that same rule still applies to the FP sets.
As much as I don't like the new crap; maybe I can still fix enough of it to finance my vintage electronics habit.
Sandy G 01-29-2010, 03:48 PM I thought the only way to fix thease damthings was w/a .45...
AUdubon5425 01-30-2010, 01:58 AM Well, you can have that 19" you looked at for me last year - it's still in my closet come to think about it.
Zenith26kc20 01-30-2010, 01:12 PM I usually find the x main or y main power supply shorted. They can be had on EBAY but after a few years, they start to eat parts.
I run my 42' LG without it's back for better cooling.
It's had three y main supplies. All go about a year and a half.
Leaving the back off stops the screw removal ritual!
Jeffhs 01-30-2010, 01:52 PM I usually find the x main or y main power supply shorted. They can be had on EBAY but after a few years, they start to eat parts.
I run my 42' LG without it's back for better cooling.
It's had three y main supplies. All go about a year and a half.
Leaving the back off stops the screw removal ritual!
Why does your set blow a Y main supply board every 18 months? Does your set work well after you replace the board? Are there any symptoms (picture pulling in, bending, etc.) which would be a tipoff that the supply is about to fail?
However, I still think three bad Y main boards, each going bad within 18 months of each other, is too much. I cannot help but think you have some kind of very major short or other problem that is overloading the supply far beyond its ratings. (Does the fuse blow before the board fails?) I'd find that short before you lose another board--they probably aren't cheap, even on eBay.
Jeffhs 01-30-2010, 02:08 PM I thought the only way to fix thease damthings was w/a .45...
If you do that, just be sure you're as far away from the set as you can get. If you shoot the front of the CRT, it will implode, sending glass fragments flying all over the place. I've seen it happen; in fact, I will never forget one day about--oh, must have been 40 years ago or so, I was about 13 years old--when I was out in the back yard in my hometown with my dad; we were going to destroy an old CRT that had been sitting in our garage for years. We wrapped the tube in an old blanket, and then we stood back and my dad threw a sledge hammer at the tube. It imploded, as expected, but one little piece of glass got into my dad's eye (probably flew out from a gap in the blanket or some such thing). Skipping the details, the shard of glass eventually worked its way (overnight) to the corner of the eye where my dad could safely remove it the following morning, but it was a very close call. Thankfully, the eye was not injured.
radiotvnut 01-30-2010, 03:19 PM I'd bet the reason he's going through so many boards is cheap parts + high temperature (these things get hot) = premature failure.
And, you won't have to worry about an implosion on an LCD or Plasma set, as they don't use CRT's.
Findm-Keepm 01-30-2010, 03:32 PM I'd bet the reason he's going through so many boards is cheap parts + high temperature (these things get hot) = premature failure.
Concur - and the heat-cool cycle is tough on the lead-free solders too. The XBOX 360 game system has a problem linked to the heat-cool cycle and lead-free solder debonding. I imagine Plasma sets aren't immune from this either with all of the heat they produce.
Cheers,
Sandy G 01-30-2010, 07:49 PM Oh, I know ALL ABOUT CRTs imploding when you shoot 'em...B&W ones anyway...Never have popped the cork on a color tube, though. CRTs make a BIG damn Melluva Hess when you use 'em for Practis De Target....(grin)
Dude111 01-30-2010, 08:59 PM I thought the only way to fix thease damthings was w/a .45...Ya they are truly pieces of garbage...
They dont produce as good a picture,etc.....
CRT has always been the BEST for producing video!! (And always will be (As analogue is the best form of sound))
Reece 01-31-2010, 06:06 AM Sounds like the heat problems could be solved with a couple of computer-type muffin fans judiciously placed next to the power supplies.
holmesuser01 02-13-2010, 10:34 AM I agree that there has to be another defect, or a serious design problem with that model. No plasma TV should have boards failing so often. I regularly see plasma TVs used as store displays running 24/7 for years before they start to fail. That's the equivalent of at least 10-15 years of home use. Have you attempted to identify the failed component?
I agree here. I run a movie theatre that has a pair of Christie (Hitachi built) flat panel sets running 18 hours a day in the lobby over the consession stand area. They've been on for over 5 years now, and still look great. I would have thought they would have died by now from running the same garbage constantly.
julianburke 02-14-2010, 12:50 PM That was an easy fix. Just wait until you get one with a black vertical line in the center or with black lines running through the picture. And there are video amps on the entire perimeter of the set itself.
radiotvnut 02-14-2010, 01:50 PM Unless I have a drastic change of heart, any future ones that I fix will be easy. Stuff like bad caps, shorted power supply diodes, blown fuses, etc. One of the local TV shops that I get stuff from will no longer work on a Plasma TV and the only LCD sets he'll fix are the easy ones.
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