Gotta TV problem
Yesterday my youngest borrowed my pick-up, telling me he had to have it right that minute. Fifteen minutes later he came back home with a HUGE projection TV in the truck. It is a Hitachi 60" diagonal HD projection TV. According to the internet it was originally offered in 1999. That sucker weighs at least 200 pounds. It took him and a muscle-bound friend to get it into the truck.
When he saw it he knocked on the front door and asked the owner why it was out at the street for the garbage people. The owner told him the sound didn't work. That seemed like a bit of a cop-out to me. The owner even thru in the remote!
When we got it home, we didn't even offload it from the truck. Ran an extension cord to the TV power supply and ran a cable extension to it. It powered up just great, and the cable input showed us a great picture. And the sound was just the way it was supposed to be. (So he lied about the sound).
So we muscled it into the house and hooked it up. It worked like a charm for about 60-90 seconds. Then the color divergence seemed to go to ca-ca. The blue-green tint seemed to be nearly 1/2 inch higher than the red tint. In other words, we had a double picture. Everything we saw on the screen was repeated on the screen, but was 1/2 inch higher on the screen, and was of a different tint.
Funny thing is that this model has a few vacuum tubes in the backside. My kid decided to to put a fan back there blowing cool air into the guts of the thing. He didn't even take the back panel off. (The back panel has a lot of 1/2 inch holes in it to facilitate internal cooling.) So far, after watching it for an hour, it is purring along as if it was fresh off the showroom floor.
They tell me that if it ain't broke, don't fix it. And I can't complain too much. But I was kinda wondering, Clearly, Hitachi didn't really design a TV that would go to sh_t because of heat problems. So why do I see these problems? Are the vacuum tubes the real culprit? Should I just shut my mouth and enjoy my good fortune?
Gotta TV problem
I would... Thermal problems aren't unusual for tubes OR semi-conductors... heat makes them work 'better' or 'faster', too much in fact, which is why a lot of offices with big computers are kept cool.
Honestly I can't remember the last time I saw a vacuum tube in a tv (besides the screen)... it makes me wonder if the tubes are part of an audio circuit, like maybe the tv has a fancy sound system, or at least better than the proverbial 4" paper speaker. A pre-amp circuit maybe... but I know nothing about projection tv's...
Anyway, it might be worth having somebody come over to look at it. Tubes are replaceable... there's a company in Indiana called SAMS, they've been around as long as television, and they publish schematics for almost every single tv and stereo ever made, last time I checked. They're like $20+, and you need more than half a clue to figure it out, but you could get the tube part numbers that way. BUT (and it's a big but..)
if you decide to take the back off LOOK OUT!
There are components that can hold lethal voltages LONG after it's unplugged.... hours, maybe days! And yes, I have gotten bit that way ...
Usually a double image or 'ghosting' is a reception issue, like the signal getting bounced off mountains or tall buildings, but that went out with rabbit ears.... Like I said, I don't know about the projection stuff... I bet there's forum about it somewhere though. Good luck!
Hey, thanks Clay,
Ghosting is the word I was looking for. Seems that thermal problems really should not be a major problem with whopper big TV sets. You'd think that the idiots would have eliminated that potential problem before they ever tried to market their piece of ca-ca.
I gotta tell ya -- it's been better than 2 hours now since we got that monster up and running with a table fan blowing cool air up it's butt, and it's IMPRESSIVE. And the cost was ---0---!
But those thermal problems are inherent in semi-conductors - whatever factory they come from, maybe one in ten thousand chips will 'give up the ghost'. Repair techs use a freezing spray to isolate which component has a thermal problem. It goes away when they hit the right one, and they know which one to replace. That stuff happens to any tv or amplifier, whatever the brand. I'll say this for Hitachi, they do make some fine power tools! Enjoy
First let me congratulate you on your good fortune. I wasn't fortuned enough when my TV broke for similar problems, something with thermal problem as well. A friend of mine fixed it for me replacing one of the parts. Since then I found a great tech support website that deals with that kinda stuff. They actually gives great tips and troubleshooting help of how to fix your TV yourself. Here is the page for the Hitachi 60" projection TV Support:
Let me know if it helped you
This message was edited Apr 5, 2007 10:42 AM