Why does my TV's picture drop out intermittently?
November 2, 2010 8:40 AM Subscribe
Why does my TV signal disappear into static for minutes or hours at a time?
I bought a Mitsubishi WS-65807 from a guy on Craigslist about a month ago, a big honking 65" rear projection TV. It is huge and awesome. We play video games on it.
When we're watching TV, though, the signal will frequently drop out. Sometimes, we will get a completely black screen (no picture), but the audio from the show will remain. Sometimes we will get light static (snow) on the screen, and the show's audio will play, but with a fair amount of noise. This often happens about 1-2 minutes after you first start to watch TV, continues for somewhere between five minutes and an hour, then goes away. When it goes away, it usually stays away for a long time. If I unplug the cable completely, the TV displays "full snow" (full brightness, full snowiness) and loud static, with no TV audio, so I know this is a partial failure.
The signal is coming from a coax jack about 3 feet away from the TV. The cable service is provided by my building (a university dorm). We've tried different coax cables- no joy. The TV has two separate tuners (it has PIP), and I've tried both tuners- they both do the same thing. Component video in (in HD) always works just fine.
I'm sort of leaning toward a thermal issue—that would explain why the signal would drop out and come back at roughly the same time from power-on—but why would it happen with both tuners? Those are separate, right? And if it's not local to the tuner, why would the other inputs work?
I'm proficient with a scope, a multimeter, and a soldering iron, and I know how to work inside a CRT, but I'm not really sure where to start inside this big hunk-o-machine. Thanks!
I bought a Mitsubishi WS-65807 from a guy on Craigslist about a month ago, a big honking 65" rear projection TV. It is huge and awesome. We play video games on it.
When we're watching TV, though, the signal will frequently drop out. Sometimes, we will get a completely black screen (no picture), but the audio from the show will remain. Sometimes we will get light static (snow) on the screen, and the show's audio will play, but with a fair amount of noise. This often happens about 1-2 minutes after you first start to watch TV, continues for somewhere between five minutes and an hour, then goes away. When it goes away, it usually stays away for a long time. If I unplug the cable completely, the TV displays "full snow" (full brightness, full snowiness) and loud static, with no TV audio, so I know this is a partial failure.
The signal is coming from a coax jack about 3 feet away from the TV. The cable service is provided by my building (a university dorm). We've tried different coax cables- no joy. The TV has two separate tuners (it has PIP), and I've tried both tuners- they both do the same thing. Component video in (in HD) always works just fine.
I'm sort of leaning toward a thermal issue—that would explain why the signal would drop out and come back at roughly the same time from power-on—but why would it happen with both tuners? Those are separate, right? And if it's not local to the tuner, why would the other inputs work?
I'm proficient with a scope, a multimeter, and a soldering iron, and I know how to work inside a CRT, but I'm not really sure where to start inside this big hunk-o-machine. Thanks!
I'd agree it sounds like a possible thermal issue - maybe something with how the coax input is set up? Given that you have the model number, you might also see if you can find a PDF of the service manual for it on line. It'll have circuit diagrams, tracing info, and the same troubleshooting info a shop would run through, plus part numbers if you wanted to try grabbing a replacement coax input board or a new tuner off ebay.
posted by BZArcher at 2:18 PM on November 7, 2010
posted by BZArcher at 2:18 PM on November 7, 2010
This thread is closed to new comments.
posted by jangie at 8:57 AM on November 2, 2010